Landsat Missions

Landsat Acronyms

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A

A&A Authorization and Authentication or Archive and Access or Associate Administrator
A&E Access and Exploration
A&P Archive and Production
A&P OPS Archive and Production Operations
A/D  Analog/Digital 
AA Active Archive or Alternative Analysis or Associated Administrator
AAC Archive Advisory Committee
AADP Active Archive Data Package
AAG Association of American Geographers
AAOS Albers Automatic Ordering System
AAR After-Action Report
AAS Anomaly Analysis Subsystem
AATHom Average Across-Track Homogeneity
ABML As-Built Materials List
ABPL As-Built Parts List
ABS Absolute
AC Alternate Current or Archive Cache or Actual Cost
ACCA  Automated Cloud Cover Assessment or Actual Cloud Cover Average
ACK Acknowledgement
ACL Access Control List
ACQ  Acquired Scenes Report 
ACRES  Australian Center for Remote Sensing 
ACS  Attitude Control System 
ACSLS Automated Cartridge System Library Software
ACTHom Average Cross-Track Homogeneity
ACU Antenna Control Unit
ACWP Actual Cost of Work Performed
AD Active Directory or Associate Director
ADA  Angular Displacement Assembly or Attitude Displacement Assembly 
ADAT Application and Data Assessment
ADC After DC Restore or Ancillary Data Corrector or Analog-to-Digital Conversion 
ADD Algorithm Description Document
ADF Ancillary Data File
ADIC Advanced Digital Information Corporation
ADM  Administrative Message 
ADML As-Designed Materials List
ADP Ancillary Data Preprocessor
ADPL As-Designed Parts List
ADS  Attitude Displacement Sensors or Angular Displacement Sensor or Archive Data Stager
ADSA  Attitude Displacement Sensor Assembly 
ADVP Algorithm Development and Verification Plan
AE Archive Element
AEA Albers Equal Area
AEM  Auxiliary Electronics Module 
AES Advanced Encryption Standard
AETD Applied Engineering and Technology Directorate
AFB United States Air Force Base
AFM Anomalous Frame Manager
AFOV Angular Field of View
AFWA  Air Force Weather Agency
AGC Automatic Gain Control
AGE  Automated Ground Equipment 
AGS  Alaska Ground Station 
AGU American Geophysical Union
AIM Algorithm Integration Meeting
AIP Archival Information Package or Annex Implementation Plan
AIS Automated Information Security
AIT Algorithm Implementation Team
AJAX Asynchronous Java Script and XML
ALG Application Layer Gateway
ALI  Advanced Land Imager 
ALIAS Advanced Land Image Assessment System
AM Artifact Mask or Analytical Modeler
AMP Allocation Management Planner
AMTS Asset Management Tracking System
AN  Ascending Node 
ANC Ancillary File
ANGCF Angle Coefficient
ANGSTT Australian National Ground Segment Technical Team
ANN Annotation File
ANS Alerts and Notifications
ANSI  American National Standards Institute 
ANSS Advanced National Seismic System
ANTLR Another Tool for Language Recognition
AO Authorization Official or Authorizing Official
AOI Area of Interest
AOS  Acquisition of Signal or Arrival On-Site or Automated Ordering System
APAC Acquisition Procurement Advisory Council
API  Application Programming Interface 
APID Application Identification
APMC Agency Program Management Council
APO Accountable Property Officer
AQ Advanced Queuing
AQPSK  Asynchronous Quadrature Phase Shift Keying 
AR Archive or Axial Ratio or Acceptance Review
ARB Architecture Review Board or Anomaly Review Board
ARC Advanced Research Computing
ARD Analysis Ready Data
ART Anomaly Resolution Team
AS Archive Server
ASA Archive Server Application or Alice Springs [Station] Australia
ASB Administrative Services Branch
ASCII  American Standard Code for Information Interchange 
ASGUI Archive Server Graphical User Interface
ASHRAE American Society of Heating, Refrigeration and Air-Conditioning
ASIC  Application Specific Integrated Circuit 
ASM Attached Sync Marker
ASN Alice Springs Ground Station or Australian Network
ASPRS American Society of Photogrammetry and Remote Sensing
ASQC American Society for Quality Control
AST  Active Scan Time 
ASTER Advanced Spaceborne Thermal Emission and Reflection
ASTER GED Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Emissivity Dataset
ASTM American Society for Testing of Materials
AT-ACCA Artificial Thermal Automated Cloud Cover Assessment
ATBD Algorithm Theoretical Basis Document
ATCS Absolute Time Command Sequence
ATHom Along-Track Homogeneity
ATK Alliant Techsystems
ATL Automated Tape Library
ATM Asynchronous Transfer Mode
ATO Authority to Operate
ATP Authority to Proceed
ATRAN Atmospheric Transmittance Layer
ATS Absolute Time Sequence or Automatic Transfer Switch
ATT Authorization to Test
AU Astronomical Units
AUI  Analyst User Interface 
AVHRR Advanced Very High Resolution Radiometer
AVI Audio Video Interleave
AVPD Avtec Programmable Demodulator
AVT Algorithm Verification Test
AWESH Automated Water Extent Shadow
AWiFS Advanced Wide-Field Sensor
AWM Analytical Workspace Manager
AWS Amazon Web Services

B

B&A  Billing & Accounting
B1 Build 1
B2B  Band-to-Band 
B2BCal Band-to-Band Calibration
BA Billing and Accounting or Burned Area
BAC Budget at Completion
BAD Block Address Data
BASIS+ Budget and Science Information System Plus
BATC Ball Aerospace & Technology Corporation
BBC Blackbody Calibrator
BBOX Bounding Box
BC Best Case
BCD  Binary-Coded Decimal 
BCH  Bose-Chaudhuri-Hocquenghem Error Detection and Correction 
BCISO Bureau Chief Information Security Officer
BCR Baseline Change Request
BCWP Budgeted Cost of Work Performed
BCWS Budgeted Cost of Work Scheduled
BD  Band 
BDA Bulk Download Application
BER  Bit Error Rate 
BERT Bit Error Rate Test
BG Build Guide
BGF Build GPR Files
BIA Business Impact Analysis or Business Impact Assessment
BIH Bureau International de l'Heure
BIL Band Interleaved by Line
BIP Band Interleaved by Pixel
BIP2 Band Interleaved by Pixel Pair
BIS Bureau of Industry and Security
BITSM Bureau Information Technology Security Manager
BJC Beijing, Peoples Republic of China Ground Station
BKT Bangkok, Thailand Ground Station
BLM Bureau of Land Management
bLMOC Backup Landsat Multi-Satellite Operations Center
BME  Browser Mean Element 
BMO Business Management Office
BMOC  Backup Mission Operations Center 
BMOE Backup Mission Operations Element
BN Background Noise
BOC Budget Object Class
BOE Basis of Estimate
BOM Bill of Materials
BP Bias Parameter
BPA Blanket Purchase Agreement
BPAL Best Practices Asset Library
BPDU  Bitstream Protocol Data Unit 
BPF Bias Parameter File
BPG Bias Parameter Generator
bps Bits per Second
BPSK  Biphase Shift Keying 
BRAA Band Registration Accuracy Assessment
BRAT Bit Rot Assessment Tool
BRDF Bidirectional Reflectance Distribution Function
BRDF-n Normalized Bidirectional Reflectance Distribution Function
BRDF-s Spectral Bidirectional Reflectance Distribution Function
BRF Bidirectional Reflectance Factor
BSP  Best Security Practices
BSQ Band Sequential
BSSC Bit Synchronizer / Signal Conditioner
BSTAR  Drag-Related Parameter in the NORAD Two-Line Element 
BSU  Baseband Switching Unit 
BTC  Bench Test Cooler 
BTF Ball Test Facility
BTI Blank Tape Interface
BTL Boot Loader
BUI Bumper mode User Interface
BUTST Bureau Unix Technical Support Team
BVR Boast Voltage Regulator
BWTST Bureau Windows Technical Support Team

C

Centigrade 
C&A Certification and Accreditation
C&DH  Command and Data Handling 
C&T Command and Telemetry
C&T DB Command and Telemetry Database
C0 Coefficient 0
C1 Coefficient 1 or Collection 1
C2 Coefficient 2 or Collection 2
C3S NPOESS Command, Control, and Communications Segment 
CA Conjunction Assessment or Control Account or Cost Account
CADU  Channel Access Data Unit 
CAGE Commercial and Government Entity
CAL Calibration Data
Cal/Val Calibration/Validation
CalCR Calibration Collection Request
CalManWG Calibration Maneuver Working Group
CALTest Calibration/Validation Test
CAM Control Account Manager or Command Authorization Meeting or Communications Security Account Manager
CAOS Collection Automatic Ordering System
CAP Cartridge Access Port or Control Account Plan
CAPE Collection Activity Planning Element
CAPERD CAPE Requirements Document
CARA Conjunction Assessment Risk Analysis
CARD Constraints and Restrictions Document
CASA Cloud and Cloud Shadow Assessment
CA-WAD Cost Account Work Authorization Document
CBA Cost-Benefit Analysis
CBB Contract Budget Base
CBC Cipher Block Chaining
CBG Configuration and Build Guide
CBN Cuiaba Earth Station
CBS Commission for Basic Systems
CC Cubic Convolution or Computer Compatible Tape or Cloud Cover
CCA  Cloud Cover Assessment  or Clinger-Cohen Act
CCB Configuration Control Board
CCD Charge-Coupled Device 
CCDC Continuous Change Detection and Classification
CCE Cryocooler Electronics
CCI Controlled Cryptographic Item
CCL Commerce Control List
CCM Cloud Cover Manager
CCMS Combined Cache Management Subsystem
CCOH Cost Center Overhead
CCP Configuration Change Process or Contamination Control Process or Cloud Cover Prediction
CCR  Configuration Change Request 
CCRS  Canada Center for Remote Sensing 
CCS COI Cleanup System or Confirmed Contact Schedule or Constellation Coordination System
CCSDS  Consultative Committee for Space Data Systems 
CCT  Computer Compatible Tape or Credit Card Transaction
CD Change Directory or Compact Disk or Cooler Door
CDB Centralized Database
CDBS Centralized Database System
CDE Common Desktop Environment
CDED Canadian Digital Elevation Dataset
CDH Command and Data Handling 
CDI  Capture Device Identifier 
CDIST Distance to Cloud
CDLR Command Data Loss Report
CDMS Carrier Doppler Measurement System
CDR Critical Design Review or Calibration Data Record or Climate Data Records
CDRL Contract Data Requirements List or Command Data Loss Report
CD-ROM  Compact Disk-Read Only Memory 
CDS Coded Data Segment or Comprehensive Discrepancy System
CDT Central Daylight Time or CPF Distribution Tool
CE Circular Error or Cognizant Employee
CE90 Circular Error 90
CEER Critical Event Readiness Review
CentOS Community Enterprise Operating System
CEOS  Committee on Earth Observing Satellites 
CER Cost Estimating Relationship
CERT Community Emergency Response Team
CES Cost Element Structure
CF Correction Factor or Cloud Fraction
CFC Contact Forecast Confirmation or Cloud Fraction Climatology
CFDP CCSDS File Delivery Protocol
CFL Conflict Notice
CFMask C version of Fmask
CFP Cold Focal Plane
CFPA  Cold Focal Plane Array or Cold Focal Plane Assembly
CFR Code of Federal Regulations or Contact Forecast Request
CGB Calculated Gains and Biases
CHS Cloud Hosting Solutions
CI  Configuration Item or Continuous Integration
CIA Confidentiality, Integrity, and Availability
CIB Controlled Image Base
CIC  Computer Interrupt Code 
CIIL Configuration Item Identifier List
CIL Critical Items List
CIO Chief Information Officer
CIRC Computer Incident Reporting Center
CIS Center for Information Security
CISO Chief Information Security Officer
CISSP Certified Information Systems Security Professional
CITT Center Information Technology Team
CIU  Controls Interface Unit 
CLCW Command Link Control Word
CLOB Character Large Object
CLR Combined Labor Rate or Contractor Labor Rate
CLTU  Command Link Transmission Unit 
CLU Climate and Land Use
cm  Centimeter 
CM  Configuration Management or Center of Mass
CMA Climate Modeling Grid - Aerosol
CMB Change Management Board
CMC Center Management Council
CMD  Command 
CMG Climate Modeling Grid
CMM  Capability Maturity Model 
CMMI Capability Maturity Model Integration
CMO Configuration Management Office
CMP  Configuration Management Plan or Change Management Plan
CMS Content Management System or Code Sync Marker
CN Coherent Noise
CNDs Could-Not-Duplicates
CNES Centre National d’Etudes Spatiales
CNNS Committee on National Security Service
CNR Carrier-to-Noise Ratio
CO Contract Officer or Content Owner
COA Cordoba, Argentina Ground Station
COC Certificate of Completion or Cost of Consequence
COFUR Cost of Fulfilling a User Request
COG Center of Gravity or Continuity of Government
COI Common Order Interface
COIGUI Common Order Interface Graphical User Interface
COLA Collision Avoidance
COMM  Communications Subsystem 
COMSEC Communications Security
Con Ops  Concept of Operations
CONAE Commission Nacional De Actividades Espaciales 
CONUS  Continental United States or Conterminous United States
COOP Continuity of Operations
COP Contingency Operating Procedure
COR Contracting Officer Representative or Cost of Reproduction
COST Calibration Operations Scheduling Tool
COTR Contracting Officer’s Technical Representative 
COTS  Commercial Off-The-Shelf 
CP Calibration Parameter or Change Proposal
CPAF Cost Plus Award Fee
CPAW Collection Planning and Analysis Workstation
CPC Contingency Plan Coordinator
CPEI Computer Program End Items
CPF  Calibration Parameter File 
CPFF Cost Plus Fixed Fee
CPI Cost Performance Index
CPIC Capital Planning and Investment Control
CPM Critical Path Methodology
CPO Custodial Property Officer
CPR Cost Performance Report
CPR1 Cost Performance Report 1
CPR4 Cost Performance Report 4
CPR5 Cost Performance Report 5
CPS Calibration Parameter Management and Testing Subsystem or COMSEC Security Plan
CPT Comprehensive Performance Test
CPU  Central Processing Unit 
CR Central Repository or Controlled Repository or Change Request or Contingency Reserve or Carriage Return or Confirmation Review
CR1 Computer Room 1
CR1MSS Computer Room 1 Mass Storage System
CR2 Computer Room 2
CR2IT Centralized Repository 2 Integration and Test
CR2OPS Centralized Repository 2 Operations
CR2ST Centralized Repository 2 System Test
CR3 Computer Room 3
CRADA NOAA Big Data Cooperative Research and Development Agreement
CRaM Combined Radiometric Model
CRC  Cyclic Redundancy Check or Cyclic Redundancy Code 
CRDEV Central Repository Development
CRI Collection Request Interface
CRIT Central Repository Integration and Test
CRM Customer Relationship Management or Continuous Risk Management
CRMP Continuous Risk Management Plan
CRMT Contingency Response Management Team
CROPS Central Repository Operations
CRS CDF Retrieval Subsystem
CRSSGS  China Remote Sensing Satellite Ground Station 
CRST Central Repository System Test
CRT Command, Ranging and Telemetry
CRTEST Central Repository Test
CS Customer Service
CSA Configuration Status Accounting or Commissioning Support Area
CSAM Cybersecurity Assessment Management
CSC  Computer Software Component
CSCI Computer Software Configuration Item
CSIRT Computer Security Incident Report Team
CSIS Control and Schedule Interface System
CSM Code Sync Marker
CSMO Chief Safety and Mission Assurance Officer
CSO Communication Services Office or Chief Safety and Mission Assurance Officer
CSOP COMSEC Standard Operating Procedure
CSR  Capture Success Rate or Capture Success Ratio or Customer Service Representative or Change System Request
CSS Cascading Style Sheet or Central Security Service or Core Science Systems
CSU   Computer Software Units 
CSV Comma Separated Values
CTDiff Cross-Track Difference
CTE Calibration Test Equipment or Compatibility Test Equipment
CTHome Cross-Track Homogeneity
CTP Command and Telemetry Processors
CTS   Capture Transfer Subsystem 
CTV   Compatibility Test Van 
CUB Cuiaba, Brazil Ground Station
CUI CPF User Interface or Controlled Unclassified Information
CV   Command Verification or Cost Variance
CV-5 Calibration and Validation 5
CV-7 Calibration and Validation 7
CVCDU  Coded Virtual Channel Data Unit 
CVCM Collected Volatile Condensable Material or Collected Volatile Condensable Mass
CVDQA Calibration Validation Data Quality Assurance 
CVE Calibration Validation Element
CVS Concurrent Versions System
CVT Calibration and Validation Team
CVTK Calibration / Validation Toolkit
CVTKRD Calibration and Validation Toolkit Requirements Document
CVWG Calibration-Validation Working Group 
CW Continuous Wave
CWBS Contractor Work Breakdown Structure
CY Contract Year

D

D&M Development and Maintenance
D/C Down Converter
D/L Downlink 
D1R DMS Generate L1R
D3 50GB Data tape cartridge from StorageTek 
DA Document Administrator 
DAAC Distributed Active Archive Center 
DACA Days After Contract Award
DAE Data Acquisition Element 
DAF Data Acquisition Facility 
DAG Database Administrator Guide
DAM Data Acquisition Manager or Database for Analysis and Modeling
DAP Data Acquisition Plan or Data Acquisition Planner
DAR Data at Rest
DART Data Access Restriction Tool
DAS Data and Applications Support
DASB Direct Access S-Band
DAT Data Access Tool
DAU Defense Acquisition University
DB Database or Data Block
dB Decibel 
dB/K Decibel per Degree Kelvin 
DBA  Database Administrator 
DBaaS Database as a Service
DBAR Database Access Routines
DBCI Database Configuration Item 
DBDD  Database Design Description  or Database Description Document
dB-Hz  Decibel-Hertz 
dBi Decibel above isotropic 
DBI Database Interface
DBMS Database Management System
DBS Data Services Branch
dBW  Decibel Relative to 1 Watt 
DC Direct Current
DC&P Data Capture and Processing Facility 
DCAA Defense Contract Audit Agency
DCCB  DHF Configuration Control Board or Development Configuration Control Board
DCE Data Collection Event
DCG DMS Generate Custom GCPLib
DCN Document Control Number or Document Change Notice 
DCO DMS Capture Order
DCOI Data Center Optimization Initiative
DCP Data Collection Planners
DCPF Data Capture & Processing Facility
DCR Document Change Request
DCRS Data Collection and Routing Subsystem or Data Collection and Routing System
DCRSf Data Collection and Routing Subsystem file router or Data Collection and Routing System file router
DCRSi Data Collection and Routing Subsystem interval router or Digital Cassette Recorder System Incremental
DCRSUI Data Collection and Routing Subsystem User Interface
DCS Data Capture System or Data Characterization Subsystem or Destination Control Statement
DCT Digital Cassette Tape 
DDD Displacement Damage Dose
DDI DCS Data Ingest
DDL Database Definition Language
DDR Data Descriptor Record
DDRC DPAS Design Reference Case
DDS DCS Database Server or Database Distribution Subsystem
DDT DPAS Test Team
DDV Dense Dark Vegetation
DE Definitive Ephemeris
DEF Definitive Ephemeris Product 
Delta-I Delta-Inclination 
DEM Digital Elevation Model 
DEPEPH Definitive Ephemeris Product 
DES Station Description Message or DAAC Emergency System
DET Escape Detection
DEU Digital Electronic Unit
DEV Development
DF Diffuser Type
DFCB Data Format Control Book 
DFD Data Flow Diagram
DFP DMS Format and Package
DFT DMS File Transfer
DG Digital Globe
DGC DMS Generate Custom GCPs
DGR DMS Generate Report Statistics
DGT DMS Generate Thumbnail
DHCP Dynamic Host Configuration Protocol
DHF Data Handling Facility 
DHN Data Handling Node
DHS Department of Homeland Security
DIAR Department of the Interior Acquisition Regulation
DIAT Daily Image Annotation Tape
DID Data Item Description or DMS Ingest L0R Data
DIE DMS Ingest Element
DIR Direction 
DIRT Data Interception by Remote Transmission
DIS Data Information System or Data Instrumentation System
DiTL Day in The Life
DIV Data Integrity Validation
DKI Parepare, Indonesia Ground Station
DLT Digital Linear Tape 
DM Data Management or Document Management or Data Manager
DMA Direct Memory Access or Defense Mapping Agency
DMAPI Data Manager Application Programmer Interface
DMB Data Management Branch
DME Development, Modernization, and Enhancement
DMF Data Migration Facility
DMI DCRS to MOE Interface
DMID Data Management and Information Delivery
DML Data Manipulation Language
DMP Document Management Plan or Data Management Policy
DMR Detailed Mission Requirements 
DMS Data Management Subsystem or Degrees, Minutes, Seconds
DMSP Defense Meteorological Satellite Program
DMU Data Migration Utility or Drag Makeup
DMZ Demilitarized Zone
DN Descending Node or Digital Number 
DNS Domain Name Server or Domain Name System
DO Delivery Order
DOC Department of Commerce 
DoD Department of Defense
DOI Department of the Interior or Digital Object Identifier
DOORS Dynamic Object-Oriented Requirements System
DOORS-NG Dynamic Object-Oriented Requirements Management System Next Generation
DOP Dilution of Precision
DOQ  Digital Orthophoto Quadrangle
DORRAN Distributed Ordering, Research, Reporting, and Accounting Network 
DoS Denial of Service
DOS Department of State
DOY Day-of-Year 
DP Data Processing
DPA Destructive Physical Analysis
DPAS  Data Processing and Archive System
DPASRD Data Processing and Archive System Requirements Document
DPD DMS Placement Daemon
DPL DMS Process L0R
DPMC Directorate Program Management Council
DPP DMS Packet and Placement
DPR DMS Process ROLO Report
DPS Data Processing Subsystem or Data Processing System
DQA Data Quality Analyst
DQV Data Quality Validation
DR Delivery Record or Discrepancy Report or Disaster Recovery or Design Review
DRA DMS Retrieve Ancillary
DRAC Dell Remote Access Controller
DRAD Downwelled Radiance Layer
DRB Discrepancy Review Board
DRC Data Requirements List
DRC-16 16-day Design Reference Case
DRE DMS Retrieve Elevation
DRFP Draft Request for Proposal
DRM DMS Resource Manager
DRP Disaster Recovery Plan
DRSF Daily Request Status File
DRTS Data Reporting and Tracking Subsystem
DSB Data Service Branch
DSI DMS Subsetter Interface
DSL Days-Since-Launch
DSN Deep Space Network
DSP Digital Signal Processor
DSS Data Staging System or DPAS Subsetter
DST Data Support Team
DSW DMS Setup Work Order
DSWE Dynamic Surface Water Extent
DTED Digital Terrain Elevation Data
DTG Daytime Group 
DTO Data Transfer Object
DTR Document Transfer Request
DTS Development and Training Simulations
DUI Data Manager User Interface or DMS Universal L0R Ingest
DUNS Data Universal Numbering System
DUZ DMS UTM Zone
DV Data Validation
DV&E Data Validation & Exchange
DVD Digital Versatile Disc
DVD-R Digital Versatile Disc – Read Only
DWF Design Web Format
DXL DMS L0 and L1 Products

E

E&A Evaluation and Analysis
E&IT Engineering and Information Technology
EA Enterprise Architecture or Executive Agency
EAC Estimate at Completion
EAR  Export Administration Regulations
EAS  Evaluation and Analysis Subsystem 
EASI Enterprise Architecture Study Implementation
EAST EROS Architecture Study Team
Eb   Energy per Bit 
Eb/N0 Energy per Bit to Noise
EBAS EROS Billing and Accounting System
EC Electronic Copy
ECA Earth Coverage Antenna
ECC Error Correction Code
ECCOE EROS Calibration / Validation Center of Excellence
ECEF Earth-Centered, Earth-Fixed
ECF Earth Centered Fixed
ECI Earth Centered Inertial
ECIMOD ECI Mean of Date
ECITOD  Earth Centered Inertial TRUE of Date 
ECL Emitter-Coupled Logic
ECMP EROS Contingency Plan Management
eCPIC Electronic Capital Planning and Investment Control
ECR Earth Centered Rotating
ECS EOSDIS Core System
ECU End Cryptographic Unit
ECV Essential Climate Variable
EDAC Error Detection and Correction
eDAR Enterprise Data At Rest
EDC   EROS Data Center 
EDDDR EDC Daily Discrepancy Report or EDC Daily Data Received Report
EDDN Emergency Data Distribution Network
EDG  EOS Data Gateway 
EDOS EOS Data Processing Segment or EOS Data and Operations System
EDU Engineering Development Unit
EE EarthExplorer
EEE Electrical, Electronic, Electromechanical
EEMT EROS Executive Management
EEO Equal Employment Opportunity
EF Earth-Fixed
EFS Encrypting File System 
E-Government Electronic Government
EGS Enterprise Ground System
EGSE Electrical Ground Support Equipment
EIA Electronic Industry Alliance
EIRP   Effective Isotropic Radiated Power 
EIS External Interface Specification
EISER EROS Information System Event Response
EJB Enterprise Java Beans
EKMS  Electronic Key Management System
EL1PS EDC Level 1 Prototype System
ELT Encumbrances, Leans, and Threats
ELV Expendable Launch Vehicle
EM Engineering Model
email Electronic Mail 
EMC Electromagnetic Compatibility
EMD Enhanced Metadata
EMI  Electromagnetic Interference
EMIS Emissivity Layer
EMP Electromagnetic Pulse
EMSD Emissivity Standard Deviation
EMV Expected Monetary Value
EN EarthNow!
ENVI Environment for Visualizing Images
EO Earth Observing
EO-1 Earth Observing 1
EOC   Earth Observation Center 
EOF End-of-File
EOIS   Earth Observation Data & Information Systems 
EOL   End-of-Line 
EOM End-of-Mission
EOMP End-of-Mission Plan
EOP Executive Office of the President
EOS   Earth Observing System 
EOSAT  Earth Observation Satellite Company 
EOSDIS   EOS Data and Information System 
EPA   Euler Parameter or ESD Protected Area
EPF ETM+ Processing Facility
EPGN EOS Polar Groundstation Network
EPP Electronic Power Converter for Payload
EPR  Engineering Peer Review
EPRP Engineering Peer Review Plan
EPS   Electrical Power Subsystem 
EPSG  European Petroleum Survey Group 
ERB Engineering Review Board
ERD Entity Relationship Diagram
EROS  Earth Resources Observation and Science
ERR   Error 
ERS EROS Registration Service
ERTS  Earth Resources Technology Satellite 
ESA   European Space Agency or Earth Sensor Assembly
ESB Enterprise Service Bus
ESD Earth Science Division or Electrostatic Discharge
ESDIS   Earth Science Data and Information System 
ESF Edge Spread Function
ESM Equipment Support Module
ESMO Earth Science Mission Operations
ESN Enterprise Services Network
ESP Encapsulating Security Payload or Engineering Specialty Plans
ESPA EROS Science Processing Architecture
ESRIN   European Space Research Institute 
ESUN Solar Spectral Irradiance or Exoatmospheric Spectral Irradiances
ETC Estimate to Completion
ETE End to End
ETL Extraction, Translation, Load or Extract, Transform, Load
ETM Enhanced Thematic Mapper
ETM+   Enhanced Thematic Mapper Plus 
ETMDSS Enhanced Thematic Mapper Plus Data Subsetting Subsystem
ETRO Estimated Time of Return to Operations
ETV Expected Time Value
EU   Engineering Unit 
EV Earned Value
EVDCU Extended Virtual Channel Data Unit
EVM Earned Value Management
EVMS Earned Value Management System
EVP Environmental Verification Plan
EVS Earth-Vehicle-Sun angle or Earned Value System
EVT Enhanced Value Technique
e-WAD Employee Work Authorization Document
EWR Eastern and Western Ranges
EWW Extended Workweek

F

F&PS   Functional and Performance Specifications 
FA Formulation Authorization
FAC   Full Aperture Calibrator 
FAD Formulation Authorization Document
FAI Federal Acquisition Institute
FAQ Frequently Asked Question
FAR Federal Acquisition Regulation
FASC   Full Aperture Solar Calibrator 
FASCAL Facility for Spectroradiometric Calibrations
FAST-L7A   FAST-Landsat 7 Format 
FAT Factory Acceptance Testing
FAX   Facsimile Transmission 
FBI Federal Bureau of Investigation
FBMS Financial and Business Management System
FC Formulation Contractor or Fiber Channel or Fractional Cover
FCA   Functional Configuration Audit 
FC-AL Fiber Channel-Arbitrated Loop
FCDAS Fairbanks Command and Data Acquisition Station
FD Flight Dynamics
FDAC Failure Detection and Control
FDC Failure Detection and Correction
FDD Facilities Definition Document or Format Description Document
FDDI  Fiber-Distributed Data Interface 
FDF  Flight Dynamics Facility 
FDIR Fault Detection, Isolation, & Recovery
FDS Flight Dynamics System
FEC Forward Error Corrected
FedRAMP Federal Risk and Authentication Management Program
FEDS Front-End Data System
FEMA Federal Emergency Management Agency
FEP Front-End Processor
FFOV Full Field of View
FFP Firm Fixed Price
FFRDC Federally Funded Research and Development Centers
FFS Fiscal Financial System
FFT Fast Fourier Transform
FFTW Fastest Fourier Transform in the West
FGDC Federal Geographic Data Committee
FHS   First Half Scan 
FHSERR First Half Scan Error
FIA Final Implementation Agreement
FIFO First In, First Out
FIPS Federal Information Processing Standards
FIR Finite Impulse Response
FISCAM Federal Information System Control Audit Manual
FISMA Federal Information Security Management Act
FISSA Federal Information System Security Awareness
Fmask Function of Mask
FMEA Failure Mode and Effect Analysis
FMECA Failure Modes, Effects, and Criticality Analysis
FMFIA Federal Manager’s Financial Integrity Act
FMT   Format 
FNMOC Fleet Numerical Meteorology and Oceanography Center
FOCCB Flight Operations Configuration Control Board
FOIA Freedom of Information Act
FOM Facilities Operations Manager
FOP   Flight Operations Plan 
FOR Flight Operations Review
FORMATS Flight Dynamics Orbit and Mission Aids Transformation System
FOS  Flight Operations Segment
FOT   Flight Operations Team 
FOTS Free Off-The-Shelf
FOV Field of View
FPA Focal Plane Assembly or Focal Plane Array
FPD Flight Projects Directorate
FPE Focal Plane Electronics
FPGA Field-Programmable Gate Array
FPM Focal Plane Modules
FPPS Federal Personnel Payroll System
FPROC Forward Processing
FQT Formal Qualification Testing
FRB  Full-Resolution Browse
FRED Framed Raw Expanded Data
FRP Federal Response Plan
FRPOC Forward Processing
FRR Flight Readiness Review
FRS File Retrieval System
FS Forecast Schedules
fSCA Fractional Snow Covered Area
FSCC Fastcom Serial Card
FSD Flight Systems Development
FSM Flight Systems Manager
FSSC Financial Support Services Contract
FSTL FST Lead
FSV Flight Software Vendor
FSW   Flight Software 
FTA Fault Tree Analysis
FTD File Transfer Daemon
FTE Full-Time Equivalent or Full-Time Employee
FTP   File Transfer Protocol 
FTR Forced to Rebalance
FTS Flight Terminiation System
FW Firewall or Full Width
FWHM Full Width Half Maximum
FY   Fiscal Year 

G

G&A General and Administrative
G/T  Gain over Temperature 
GAfG Google Apps for Government
GAM Geography Analysis and Monitoring
GAO General Accounting Office
GAQD Originator Routing Code for IIRV Messages
GAR Global Archive Refresh
GARD Global Analysis Ready Data
GAST Greenwich Apparent Sidereal Time
GB   Gigabyte 
GbE Gigabit per Second Ethernet
GBFOM Global Band Figure of Merit
GBICS Gigabit Interface Converters
GBL Government Bill of Lading
Gbps Gigabits per Second
GCCB Ground Segment Configuration Control Board
GCDR Ground System Critical Design Review
GCOR Temperature Corrected Gains
GCP Ground Control Point
GCRS Geocentric Celestial Reference System
GCTP General Cartographic Transformation Package
GDAIS General Dynamics Advanced Information Systems
GDAL Geospatial Data Abstraction Library
GDP Gross Domestic Product
GDS Ground Data Systems
GED Global Emissivity Database
GEDU Ground Encryption / Decryption Unit
GEO   Geolocation Index File 
GEOM Geometric
GeoRSS Geographic Really Simple Syndication
GeoTIFF  Geographic Tagged Image File Format 
GES DISC Goddard Earth Sciences Data and Information Services Center
GEVS General Environmental Verification Specification
GFE Government Furnished Equipment
GFP Government Furnished Property
GFS Global File System
GFY Government Fiscal Year
GHz Gigahertz
GIA Government Inspection Agency
GIAC Global Information Assurance Certification
GIDEP Government Industry Data Exchange Program
GigE Gigabit Ethernet
GIO Geographic Information Officer
GIPS   Geoinformatics Products and Solutions 
GIS Geographical Information Systems
GISRA Government Information Security Reform Act
GISTDA   Geoinformatics and Space Technology Development Agency (Thailand) 
GL Geoscience Laboratory
GLAMR Goddard Laser for Absolute Measurement of Radiance
GLC  Ground Look Calibration Request or Gilmore Creek
GloVis Global Visualization Viewer
GLS Global Land Survey or Global File System
GMAP Global Monitoring Acquisition Plan
GMSEC Goddard Mission Services Evolution Center
GMSR Government Monthly Status Review
GMT   Greenwich Mean Time 
GN   Ground Network 
GNC Gatineau, Canada Ground Station
GNE Ground Network Element
GNE-DCRS Ground Network Element Data Collection and Routing System
GNEDD Ground Network Element Design Document
GNERD GNE Requirements Document
GOES Geostationary Operational Environmental Satellite
GOLD Goddard Open Learning Design
GOP Ground Operations Plan
GOS Geospatial One-Stop
GOT Ground Operations Team
GOTS Government Off-The-Shelf
GP4   General Perturbation Theory 
GPD GSFC Policy Directive
GPDR Ground System Preliminary Design Review
GPL General Public License
GPR GNE Post-Pass Report or Goddard Procedural Requirement
GPS   Geometric Processing System or Gap Phase Statistic or Global Positioning System
GRASS Geographic Resources Analysis Support System
GRI Ground Reference Image
GRIB Gridded Data or Gridded Binary
GRID Global Resource Information Database
GRM Ground Readiness Manager
GRS Grid Reference System (SPOT)
GRT Ground Readiness Test
GRTP Ground Readiness Test Plan
GRTT Ground Readiness Test Team
GS Ground System or Ground Segment
GSA U.S. General Services Administration or Ground Station Analyst
GSC  Ground Station Controller 
GSCCB Ground System Change Control Board
GSCDR Ground System Critical Design Review
GSD Ground Sampling Distance or Guide Star Data
GSDD Ground System Design Document
GSDRB Ground System Discrepancy Review Board
GSE Ground Support Equipment or Ground Station Engineers or Ground System Engineer
GSFC   Goddard Space Flight Center 
GSI   Ground Station Identifier or Ground System Infrastructure or Ground Support Infrastructure
GSICS Global Space-based Intercalibration System
GSIRD Ground System Interface Requirements Document
GSIT Ground System Integration
GSITP Ground System Integration and Test Plan
GSIWG Ground System Interface Working Group
GSL GNU Scientific Library
GSM Ground System Manager
GSMO Ground System Management Office or Ground System and Mission Operations
GSMOR Ground System Mission Operations Review
GSOCD Ground System Operations Concept Document
GSOPD Ground System Operations Plan Document
GSPDR Ground System Preliminary Design Review
GSRD Ground System Requirements Document 
GSRR Ground System Requirements Review
GSRT Ground System Review Team
GSRVM Ground System Requirements Verification Maintenance
GSSP Guide for Developing Security Plans for Information Technology Systems
GST Geographic Support Team or Ground Station Technician
GSTDN Ground Spaceflight Tracking and Data Network 
GSVVP Ground System Verification and Validation Plan
GSVWG Ground System Verification Working Group
GSWG Ground System Working Group
GTOPO30 Global 30 Arc-Second Elevation Data Set
GUI   Graphical User Interface 
GXA   Gimbaled X-Band Antennae 

H

H/W Hardware
HA High Availability
HAAT Header, Ancillary, Annotation, and Trailer
HC Hard Copy
HCA Horizontal Collimator Assembly
HCR Hardware Configuration Request or Hardware Change Request
HDDS Hazards Data Distribution Systems
HDF   Hierarchical Data Format 
HDF5 Hierarchical Data Format Version 5
HDF5-EOS Hierarchical Data Format Version 5 - Earth Observing System
HDF-EOS Hierarchical Data Format - Earth Observing System
HDFS Hadoop File System
HDLC High-Level Data Link Control
HDM Hardware Data Manager or HSM Data Manager
HDP HDF Dumper
HDR   Header 
HDRM High Data Rate Modem
HDS Horizontal Display Shift
HDT   High-Density Tape 
HDTR High-Density Tape Recorder
HE Hardware Engineer
Hex   Hexadecimal 
HgCdTe Mercury Cadmium Telluride
HGS Hallway Ground Station
HK Housekeeping
HLD High-Level Document
HMP Hardware Management Plan
HOM Hotine Oblique Mercator
HOMFiH Homogeneity Filter
HPA High-Power Antenna
HPN Panchromatic Band Header File
HPP Highest Point in Polygon
HQ Headquarters
HR Human Resources or Heritage Review
HR MSI High-Resolution Multispectral Imager
HRS Horizontal Resampling Space
HRV High-Resolution Visible (SPOT sensor)
HSM Hierarchical Storage Management or Hierarchical Storage Manager
HSPD Homeland Security Presidential Directive
HTM Thermal Bands Header File
HTML   Hypertext Markup Language 
HTSI Honeywell Technology Solutions Inc.
HTTP   Hypertext Transfer Protocol 
HTTPS Hypertext Transfer Protocol Secure
HUB Historically Underutilized Business
HVAC Heating, Ventilation, & Air Conditioning
HVU High-Volume User
HWCI   Hardware Configuration Item 
Hz  Hertz 

I

I   In-Phase Channel 
I&T Integration and Test 
I/O   Input/Output or In-Phase and Quadrature Modulation Components
I1 Internet 1
I2 Internet 2
I2I Image-to-Image
I2RV   Improved Inter-Range Vector Message 
IA Implementing Agreement or Impact Analysis or International Activities or Interagency Agreement
IAA Interagency Agreement
IaaS Infrastructure as a Service
IAC Independent Assurance Contractor or Issue Assessment Code
IAD Ion-Assisted Deposition
IAS Image Assessment Subsystem or Image Assessment System
IASICP IAS Internal Calibrator Pulse
IATO Interim Authority To Operate
IAU International Astronomical Union
IAW In Association With
IBM International Business Machines
IBR Integrated Baseline Review
IC Interface Control or International Cooperator or Internal Calibrator or Internal Cache
ICD  Interface Control Document 
ICDR Instrument Critical Design Review
ICe Internal Calibrator processing for Emissive bands
ICF Initial Correction Factor
ICMP Internet Control Message Protocol
ICO International Cooperator Office
ICT Interface Connectivity Testing
ICVS Independent Calibration and Verification Segment or Independent Characterization and Verification System
ICWP IC Web Portal
ID Infrastructure Design or Interface Documents or Identification
IDCC Interval Data Collection Concept
IDCO Image Data Collection Omission
IDCS Image Data Collection Schedule
IDD Interface Definitions Document
IDE Integrated Device Electronics or Infrastructure Development or Integrated Development Environment
IDF Interval Definition File or Image Data File
IDIQ Indefinite Delivery Indefinite Quantity
IDL Interactive Data Language
IDP Individual Development Plan
IDPS Image Data Processing Subsystem 
IDR IAS Data Recorder
IDS  Intrusion Detection System or Interval Delivery Subsystem
IDSO Image Data Schedule Omission
IDSR Image Data Schedule Report
IDWR Idaho Department of Water Resources
IE Infrastructure Element
IEC iStat Executive Committee or International Electrotechnical Commission
IEEE  Institute of Electrical and Electronics Engineers 
IEM Integrated Electronics Module
IERS International Earth Rotation Service
IETF Internet Engineering Task Force
IF Intermediate Frequency
IFAT ITOS File Accounting Tool
IFFT Inverse Fast Fourier Transform
IFL Interfacility Link
IFOV   Instrument Field of View or Instantaneous Field of View 
IGE Independent Government Estimate
IGMP Internet Group Management Protocol
IGS Integrated Security Gateway or International Ground Station
IIOP Internet Inter-ORB Protocol
IIR Image Impact Report
IIRR Instrument Integration Readiness Review
IIRV   Improved Inter-Range Vector 
IKE Internet Key Exchange
ILI IGS to LAM Interface
IM Instant Message or Inclination Maneuver
IMB Issue Management Board
IMF Inverse Minor Frames or Interval Metadata File
IMP Information Management Plan or Integrated Master Plan
IMR Issue Management Record
IMS  Integrated Master Schedule or Information Management System
IMT Integrated Mission Timeline
IMU   Inertial Measurement Unit or Internal Measurement Unit 
IMWD Internet Moving Window Display
IN Impulse Noise or Ingest
INCOSE International Council on Systems Engineering
INFOSEC Information Security
ING Ingest
INM IGS Network Manager
INPE   National Institute for Space Research 
InSb Indium Antimonite
INV Inventory
IOC Initial Operational Capability or Initial On-orbit Checkout or Installation Operational Certification or In-Orbit Checkout or Initial Operational Configuration
IOE Instrument Operations Element 
IONET IP Operational Network
IP  Internet Protocol or Installation Plan or Intellectual Property
IPA Interproject Agreement or Instrument Pallet Assembly
IPAC Intergovernment Payment and Collection
IPC Institute for Interconnecting and Packaging Electronic Circuits or Inter-Process Communication
IPComp IP Payload Compression Protocol
IPDR Instrument Preliminary Design Review
IPDS Information Product Data System
IPDU Internet Protocol Data Unit
IPE Image Processing Element
IPM IGS Priority Mask Online Tool or IGS Priority and Request Map or Incyte Project Manager
IPMR Integrated Program Management Report
IPMS Integrated Project Management System
IPMSD Integrated Project Management System Description
IPO Integrated Program Office
IPP Invoice Processing Platform
IPR  Intersegment Problem Report 
IPS  Intrusion Prevention System or Image Processing Subsystem
IPSec Internet Protocol Security
IPSR Instrument Preship Review
IPT Integrated Project Team or Integrated Product Team
IPV Integrated Pulse Value
IR Infrared
IRB Investment Review Board
IRD Interface Requirements Document
IRFP Implementation Request for Proposal
IRIG Inter-Range Instrumentation Group
IRP Incident Reporting Plan
IRR Integrated Readiness Review
IRS   Interface Requirements Specification 
IRU Inertial Reference Unit
IRV Improved Inter-Range Vector Message
IS Ingest System
ISA Internet Security and Acceleration or Interconnection Security Agreement
ISCCP International Satellite Cloud Climatology Project
ISCP Information System Contingency Plan
iSCSI Internet Small Computer System Interface
ISD Interface Specification Document
ISF Instrument Support Facility
ISI Integral Systems Incorporated
ISL Interswitch Link
ISO   International Standards Organization 
ISRO Indian Space Research Organization
ISSLOB Information Systems Security Line of Business
ISSO Information System Security Official
IST Integrated System Test
ISTESR Ingest Subsystem Test Execution Summary Report or Inventory Subsystem Test Execution Summary Report
IT Information Technology or Integration Test
ITAR International Traffic in Arms Regulations
ITC Integration Test Case
ITOS Integrated Test and Operations System
ITRS International Terrestrial Reference System
ITS Information Technology Services or Integrated Time Sweep
ITSEC Information Technology Security
ITSNOC Information Technologies Service Network Operations Center
ITSOT Information Technology Security Operations Team
ITSS   Information Technology and Scientific Services 
ITU International Telecommunications Union
IU Individual User
IUR Individual User Request
IV&V Independent Verification and Validation
IVM Interface Verification Matrix
IW&DS Information Warehouse and Data Store
IWAD Individual Work Authorization Document
IWG   Interface Working Group 
IWT Image Window Table

J

J2EE Java 2 Platform, Enterprise Edition
JAR Java Archive
JASON Joint Activity Simulation for Observatories and Networks
JAXA Japan Aerospace Exploration Agency
JaxB Java Architecture for XML Binding
JBOD Just a Bunch Of Disks
JBOSS J2EE Application Server
JCL Joint Confidence Level
JDBC Java Database Connectivity
JDK Java Development Kit
JFIF JPEG File Interchange Format
JMS Java Messaging Service
JMSRA Java Message Service Resource Adapter
JPEG   Joint Photographic Experts Group 
JPF Job Parameter File
JPL   Jet Propulsion Laboratory 
JSA Johannesburg, South Africa Ground Station
JSP Java Server Pages
JSpOC Joint Space Operations Center
JSR Java Portlet Specification
JTS Java Topology Suite
JVM Java Virtual Machine

K

Degrees Kelvin 
KA8 Known Anomaly Eight
KB   Kilobyte 
KBps Kilobytes per Second
KDP Key Decision Point
kg Kilogram
KHB Kennedy Space Center Handbook
KHC Kashi, China Ground Station
kHz   Kilohertz 
KIS Kiruna, Sweden Ground Station
km   Kilometer 
KMI Key Management Infrastructure
KML Keyhole Markup Language
KMP Key Management Plan
KPI Key Performance Indicator
KPM Key Performance Measures
KPR Key Performance Requirement
KSAT Kongsberg Satellite Services
KSC Kennedy Space Center
Ksps Kilo-Symbols per Second
KUJ Kumamoto, Japan Ground Station
KVM Keyboard Video Mouse

L

L&EO Launch and Early Orbit
L+30 Launch + 30 Days
L+60 Launch + 60 Days
L+90 Launch + 90  Days
L0 Level 0
L0c Level 0 Corrected
L0R  Level 0 Reformatted
L0Ra  Level 0 Reformatted Archive 
L0Rc Level 0 Reformatted Corrected
L0Rp  Level 0 Reformatted Product
L1  Level 1 or Landsat 1
L1AOS Level 1 Automatic Ordering System
L1G   Level 1 Systematic (Corrected)
L1Gs Level 1 Geometric Systematic
L1Gt Level 1 Systematic Terrain (Corrected)
L1P Level 1 Precision (Corrected)
L1R  Level 1 Radiometric (Corrected) 
L1R-H Hybrid Level 1 Radiometric
L1SE Level 1 Sustaining Engineering
L1T Level 1 Terrain (Corrected) or Level 1 Precision and Terrain
L1TP Level 1 Terrain Precision (Corrected)
L2 Level 2 or Landsat 2
L2+ Level 2+
L2GT Level 2 Systematic Terrain (Corrected)
L2PGS Level 2 Product Generation System
L2PS Level 2 Science Product
L2TP Level 2 Terrain Precision (Corrected)
L3 Level 3 or Landsat 3
L3+ Level 3+
L4 Level 4 or Landsat 4
L5  Landsat 5 
L7   Landsat 7 
L8 Landsat 8
L9 Landsat 9
LAADS Landsat Atmosphere Archive and Distribution System
LACCA Land Automated Cloud Cover Assessment
LACS Landsat Archive Conversion System
LADS LDCM Archive and Dissemination Segment
LAM   Landsat Archive Manager 
LAM AS LAM Archive Server
LAM008 Interface Between COI PS and L0Rp PS
LAN   Local Area Network 
LANDSAT Land Satellite
LAS  Land Analysis System 
LASP   Laboratory for Atmospheric and Space Physics 
LaSRC Land Surface Reflectance Code or Landsat 8 Surface Reflectance Code
LAT   Latitude or Lab Acceptance Test
LBG Libreville, Gabon Ground Station
LC LDCM Contractor
LCC  Lambert Conformal Conic or Lifecycle Cost
LCCB Landsat Configuration Control Board
LCCR Landsat Configuration Change Request
LCG  Landsat Coordination Group 
LCGS LDCM Contractor Ground Segment
LCMAP Land Change Monitoring Assessment and Projection
LCR Logical Change Record or LTAP Collection Request
LCSS LDCM Contractor Space Segment
LDAP Lightweight Directory Access Protocol
LDB IAS Local Database
LDCC Landsat Data Continuity Contract
LDCM  Landsat Data Continuity Mission 
LDCMGS Landsat Data Continuity Mission Ground Station
LDCMSC Landsat Data Continuity Mission Spacecraft
LDDMWG Landsat Data Distribution and Marketing Working Group
LDDWG Landsat Data Distribution Working Group
LDI LPS Data Ingest or L0Ra Data Ingest
LDIF LDAP Data Interchange Format
LDIS LAM to DORRAN Interface System
LDPC Low-Density Parity Check
LDPS Landsat Data Purchase System
LDRCS LDCM Document Review Comment Spreadsheet
LDTS  LPS Data Transfer Subsystem 
LEDAPS Landsat Ecosystem Disturbance Adaptive Processing System
LEI LAM to ECS Interface
LEM   Lower Equipment Module 
LEO Low-Earth Orbiting or Launch and Early Orbit
LEO&A Launch, Early Orbit and Activation
LEO-T Low-Earth Orbiter-Terminal
LES Log file Extraction Services
Level A Level Zero Aggregated
LF Line-Feed
LG L0Ra Generator
LGAC Landsat Global Archive Consolidation
LGGS Landsat Global Geodetic Standard
LGN   Landsat Ground Network
LGNT Landsat Ground Network Test
LGPL Lesser General Public License
LGS Landsat 7 Ground System or Landsat Ground Station
LGSOWG Landsat Ground Station Operations Working Group 
LH Left Hand
LHC   Left-Hand Circular 
LHCP Left-Hand Circularly Polarized
LHS Left-Hand Side or Left-Hand SLO
LIB Library
LICS Landsat International Communication System
LID Landsat and LDCM Inventory Database or LSDS Inventory Database
LIFO Last In, First Out
LIL Landsat Inventory Loader
LIM Landsat Inventory Management or LDCM Interface for Metadata
LIMA Landsat Image Mosaic of Antarctica
LIMB LAM Interface for Metadata and Browse
LINEAGEQA Lineage Index
LIR LDCM in Retrospect
LIS Landsat Integration System or LACS Inventory System
LISS-III Linear Imaging Self-Scanning Sensor III
LITAP   Landsat Intersegment Technical Assessment Panel 
LL   Lower Left 
LLI LAM to LACS Interface
LLIS LAM LPGS Interface Subsystem
LM Labeled Mask
LMASK Labeled Mask
Lmax Maximum Radiance
LMC  Lockheed Martin Corporation 
LMCM Launch Management Coordination Meeting
LMD Landsat Mission Database
LMDD Landsat Metadata Description Document
LMDRS Landsat Metadata Documentation and Reporting System
LMI  Lower Equipment Module Interface 
LMM Landsat Mission Manager
LMMS   Lockheed Martin Missiles and Space 
LMO Landsat Mission Operations
LMOC Landsat Multi-Satellite Operations Center
LMOCRD Landsat Multi-Satellite Operations Center Requirements Document
LMOO LMO Ops Crew
LMOP Landsat Mission Operations Project
LMST Local Mean Solar Time
LMWS Landsat Missions Website
LNA Low-Noise Amplifiers
LNET Lustre Networking
LO Local Oscillator
LOA Letter of Agreement
LOC Letter of Cooperation or Line of Code
LOE Level of Effort
LON  Longitude 
LOOFA Landsat 7 On-Orbit Flight Automation
LOP Landsat Operational Procedure
LOS  Loss of Signal or Line-of-Sight 
LP DAAC  Land Processes Distributed Active Archive Center 
LPDS Level 1 Product Distribution System or LDCM Data Product Specification 
LPGS Landsat Product Generation System
LPGSUI Level 1 Product Generation Subsystem User Interface or Landsat Product Generation System User Interface
LPIP Landsat Product Improvement Project
LPO  Landsat Program Office or LSDS Program Office
LPS   Landsat 7 Processing System 
LPSNG Landsat Processing System Next Generation
LPSO   Landsat Project Science Office 
LPT Limited Performance Test
LR  Lower Right 
LRD Launch Readiness Date
LRMB LDCM Risk Management Board 
LRR Launch Readiness Review
LRS Landsat Remote Sensing
LRSP Land Remote Sensing Program
LS Launch Segment
LSAA Landsat and Sentinel-2 Archive / Access or Landsat Sentinel Archive Access
LSATH High-Saturation Radiance
LSATL Low-Saturation Radiance
LSB   Least Significant Bit or Low Surface Brightness
LSC Landsat Security Committee
LSCF Landsat Solar Calibration Frame
LSDS Land Satellites Data System
LSF Line Spread Function
LSIMSS LDCM Scalable Integrated Multi-Mission Support System or Landsat Scalable Integrated Multi-Mission Support System or Landsat Scalable Integrated Multi-Mission Simulation System
LSIS Landsat Science Information System
LSO LDCM Science Office or LSRD Science Office
LSP Launch Support Program or Logistics Support Plan
LSQ Least Squares
LSQAT Landsat Science Quality Assurance Team
LSR Launch Support Room
LSRD LSDS Science Research and Development
LSS Launch Services Segment
LST Landsat Science Team or Land Surface Temperature or Landsat Surface Temperature
LTA Long-Term Archive
LTAP Long-Term Acquisition Plan
LTAP-7 Landsat 7 Long-Term Acquisition Plan 
LTAP-8 Landsat 8 Long-Term Acquisition Plan
LTAP-9 Landsat 9 Long-Term Acquisition Plan
LTAS   Landsat Trending and Analysis System 
LTI Legacy Tape Ingest
LTO Linear Tape Open
LTS  LACS Transcription System
LTVA Limited Technical Vulnerability Assessment
LTWG  Landsat Technical Working Group 
Ltypical Typical Radiance
LUN Logical Unit Number
LUT Look-Up Table
LV Launce Vehicle
LVDT Linear Variable Differential Transformer
LVRR Launch Vehicle Readiness Review
LWIR   Long Wavelength Infrared 
LXR Landsat Transfer Radiometer

M

m   meter 
M&PCB Materials and Processes Control Board
M&PCP Materials and Processes Control Program
M2M Machine-to-Machine
MA Mission Archive or Multiple Access or Major Application or Mission Assurance
MAC   Media Access Control or Monitor and Control Subsystem
MACS MSS-X Archive Conversion System or Monitor and Control Subsystem
MAD Median Absolute Deviation
MAE Materials Assurance Engineer
MAID Massive Array of Idle Disks or Master Action Item Database
MAM Mission Assurance Manager
MAP Mission Assurance Plan
MAR Mission Assurance Requirements
MAS   MODIS Archive System 
MB   Megabyte 
MBO Management by Objects
Mbps   Megabit per Second 
MBSRN Multiband Spectral Relationship Near-Infrared
MBSRV Multiband Spectral Relationship Visible
MC MAC Controller
MCDL Master Configured Document List or Master Controlled Document List
MCDR Mission Critical Design Review
M-CDR MOC Critical Design Review
MCE Mirror Control Electronics
MCM Multichip Module
MCR Mission Concept Review
MCS   Monitor and Control Subsystem 
MD Metrics Database or Mission Data
MD5 Message-Digital Algorithm 5 or Message-Digest Algorithm 5
MDA MacDonald, Dettwiler, and Associates
MDGLS Mid-Decadal Global Land Survey
MDH Mission Data Header
MDIO Mission Data Input / Output
MDL Metadata Loader
MDM Mission Data Management
MDR Mission Dress Rehearsal or Mission Definition Review
MDS   MMO Database System or Metadata Server
MDT Metadata Target
ME Memory Effect
MEB Materials Engineering Branch or Main Electronics Box or McMurdo, Antarctica, or Main Electronics Board
MEC Metrics ETL Component
MEF Mission Essential Function
MEO Matrixed Engineering Organization
MEOS Multi-Mission Earth Observation System
MER Mission Equipment Room
MERRA Modern-Era Retrospective Analysis for Research and Application
MF  Minor Frame 
mf  minor frame
MFC Microsoft Foundation Classes or MAC Fetch CPF
MFPS  Major Frame Processing Subsystem 
MFR Multifunctional Receiver
MG Metadata Generator
MGS   MODIS Ground Station or Management Server
MGT Management Target
MHz   Megahertz 
MI Mutual Information
MIL Materials Identification List or MAC Inventory L0Ra
MIS Master Integrated Schedule or Management Information System
MISR Multiangle Imaging Spectroradiometer
MISTE Modular Integrated Simulation and Test Environment
MIT Massachusetts Institute of Technology
MJF Major Frame
MJP MAC Job Processor
MLC Most Likely Case
MLDRCS Master LDRCS
MLH Maximum Likelihood Estimate
MLI MACS to LAM Interface 
MLT   Mean Local Time 
MM Multi-Mission or Mission Manager
mm   Millimeter 
MM&A Mission Monitor & Analysis
mm/hr   Millimeters per Hour 
MMA Mission Management Analyst
MMIO Modified Moravec Interest Operator
MMO Mission Management Office
MMOIO Mission Management Office Information Officer
MMOSA MMO Security Activity
MMOSE Mission Management Office Systems Engineer
MMR Mission Requirements Review
MMS MDGLS Management System or Multi-Mission Modular Spacecraft
MNDWI Modified Normalized Differences Wetness Index
MO&DSD   Mission Operations and Data System Directorate 
MOA Memorandum of Agreement
MOC   Mission Operations Center 
MOCRD Mission Operations Requirement Document
MODIS   Moderate Resolution Imaging Spectrometer 
MODNET   MO&DSD Operational/Development Network 
MODTRAN Moderate Resolution Transmittance atmospheric modeling software
MOE Mission Operations Element
MOERD Mission Operations Element Requirements Document
MOI Moment of Inertia
MOM Mission Operations Manager
MOP Mission Operations Plan
MOPSS   Mission Operations Planning and Scheduling System 
MOR Mission Operations Room or Mission Operations Review
MORM Mission Operations Readiness Manager
MOS Mission Operations Simulation
MOTS Mission Off-The-Shelf or Military Off-The-Shelf
MOU   Memorandum of Understanding 
MOVE Mission Operations Voice Enhancement
MOWG Mission Operations Working Group
MP Multiprocessor
M-PDF MOC Preliminary Design Review
MPEG Moving Picture Experts Group
MPLS Multiprotocol Label Switching
MPR Monthly Progress Review 
MPS MODIS Processing System or Mission Plan System
MPSR Management Program Status Review or Monthly Project Status Report
MR Management Reserve
MRB Milestone Review Board or Material Review Board
MRC Metrics Reporting Component or Metadata Record
MRG Metrics Report GUI
MRLC Multiresolution Land Characteristics
MRR Mission Requirements Review
MRT Mission Readiness Testing
MRTG Multirouter Traffic Grapher
MS Multispectral
ms   millisecond 
MSA Master Schedule of Activities
msb   Most Significant Bit 
MSB   Most Significant Byte 
MSCD   Mirror Scan Correction Data 
MSE Mission Systems Engineering
MSFC Marshall Space Flight Center
MSI Multispectral Instrument
M-SIR MOC System Integration Review
MSK   Receive Antenna Horizon Mask Message 
MSM Multiservice Mobility or Mission Simulations Manager or Management Switch Module or Mission Operations Center Systems Manager
MSO Mission Support Office
Msps Mega-Symbols per Second
MSPSP Missile System Prelaunch Safety Data Package
MSR Monthly Status Review
M-SRR MOC System Requirements Review
MSS   Multispectral Scanner or Mass Storage System
MSS-A Multispectral Scanner - Archive Format
MSS-P Multispectral Scanner - Processed Format
MSS-X Multispectral Scanner data, reformatted CCT-X data
MST Mission Support Team
MTA   Metadata 
MTASS Multi-Mission Three-Axis Stabilized Spacecraft
MTBF Mean Time Before Failure
MTDSS MS and TM Data Subsetting System
MTF   Modulation Transfer Function 
MTFC   Modulation Transfer Function Compensation 
MTHR Mission Transition Handover Review
MTI Matera, Italy
MTL Level 1 Metadata or Metadata Text File Extension
MTP   Distribution Product Metadata 
MTR Mission Transition Review
MTS MDS Transformation Services
MTTR Mean Time to Restore or Mean Time to Repair or Mean Time to Recovery
MTU Maximum Transmission Unit
MUA Materials Usage Agreement
mW   milliWatt 
MWD Moving Window Display

N

N/A   Not Applicable 
N/T Normal-Through
N0   Noise Density 
NAD83 North American Datum of 1983
NAK Negative Acknowledgement
NARA National Archive and Records Administration
NARR North American Regional Reanalysis
NAS NASA Assurance Standard or Network Attached Storage
NASA   National Aeronautics and Space Administration 
NASCOM NASA Communications 
NASDA   National Space Development Agency (Japan) 
NAVOCEANO Naval Oceanographic Office
NB Narrow Band
NBAR Nadir Bidirectional Reflectance Distribution Function Adjusted Reflectance
NBII National Biological Information Infrastructure
NBR Normalized Burn Ratio or Navigation Base Reference
NCAS   National Carbon Accounting System 
NCC   Network Control Center 
NCEP National Centers for Environmental Prediction
NCSA   National Center for Supercomputing Applications 
NCT Network Connectivity Test
NDA Non-Disclosure Agreement
NDE Non-Destructive Examination
NDF   NLAPS Data Format 
NDI Non-Development Items
NDIA National Defense Industrial Association
NDP National Satellite Land Remote Sensing Data Archive (NSLRSDA) Data Package
NDPF NASA Data Processing Facility
NDSI  Normalized Difference Snow Index
NDVI Normalized Difference Vegetation Index
NErT Noise Equivalent Delta Temperature
NED Natural Elevation Data
NEDL Noise Equivalent Detector Radiance
NEDT Noise Equivalent Detector Temperature
NEMA National Electrical Manufacturers Association
NEN Near Earth Network
NENUG Near Earth Network User’s Guide
NEOG National Earth Observation Group
NEOS  National Earth Orientation Service 
NEPAG NASA EEE Parts Assurance Group
NESDIS  National Environmental Satellite Data and Information Service 
NetCDF Network Common Data Form
NewOps New Operational Procedures System
NEX NASA Earth Exchange
NFS  Network File System
NG National Guard
NGA National Geospatial Intelligence Agency
NGAC National Geospatial Advisory Committee
NGIS Northrop Grumman Innovation Systems
NGST Northrop Grumman Space Technology 
NH Northern Hemisphere
NHB NASA Handbook
NIC Network Interface Card
NIFC National Interagency Fire Center
NIOB Niobrara, Nebraska
NIPD Network Interface Planning Document
NIR Near-infrared
NISN NASA Integrated Services Network 
NIST National Institute for Standards and Technology
NITF National Imagery Transformation Format
NLAPS   National Land Archive Production System 
NLCD National Land Cover Dataset or National Land Cover Database
NLI National Land Imaging
NLIP National Land Imaging Program
nm Nanometer
NMAS  National Map Accuracy Standards
NMD National Mapping Discipline
NMS Network Management Software
NN Nearest Neighbor
NOA New Obligating Authority
NOAA  National Oceanic and Atmospheric Administration 
NOC NUGS Operations Concept
NOLAN  Nascom Operational Local Area Network 
NOM Network Operations Manager
NOR  NORAD Two Line Element Message 
NORAD  North American Air Defense or North American Aerospace Defense Command
NOVAS Naval Definition Vector Astronomy Software
NP Narrative Procedure
NPD NASA Policy Directive
NPOESS National Polar-orbiting Operational Environmental Satellite System
NPR NASA Procedural Requirements
NPS National Park Service
NPSL NASA Parts Selection List
NPV  Net Present Value or Net Pulse Value
NRCA Nonconformance Reporting and Corrective Action
NRT Network Readiness Test
NRTL Nationally Recognized Testing Laboratory
NRZ-L   Non-Return to Zero-Level 
NRZ-M   Non-Return to Zero-Mark 
NSA National Security Agency
NSC Norwegian Space Centre
NSDI   Normalized Snow Difference Index or National Spatial Data Infrastructure
NSF National Science Foundation
NSG Neustrelitz, Germany Ground Station
NSLRSDA National Satellite Land Remote Sensing Data Archive
NSM Network and Security Manager
NSN/NSG Neustrelitz Ground Station (Germany)
NSPAR Nonstandard Parts Approval Request
NSS NASA Safety Standard
NSSDC National Space Science Data Center
NSTC National Science and Technology Council
NTE Not-To-Exceed
NTIA National Telecommunications and Information Administration
NTP Network Time Protocol
NTR New Technology Report
NUC Non-Uniformity Correction
NUGS NASA-USGS Joint Ground System
NUP North Up
NWIS National Water Information System
NWP Numerical Weather Prediction
NWS National Weather Service

O

O&M Operations & Maintenance
O&S Operations & Sustaining
OA Operational Archive or Operations Agreement or Operations Analyst or Orbital Alliant Tech Systems
OAG Office of Acquisitions and Grants
OAR On-Orbit Acceptance Review or Operational Acceptance Review
OAV Operational Verification Assessment
OBC Onboard Computer or Onboard Calibrator
OBE Overcome By Events
OBP Onboard Processor
OBS Organizational Breakdown Structure
Obs-IRD Observatory Interface Requirements Document
OC Online Cache or Operations Concept
OCAO Office of the Chief Administrative Officer
OCC Operator Control Console or Occurrence
O-CCB Operations Configuration Control Board
OCD Operations Concept Document
OCE Office of Chief Engineering
OCI Organization Conflict of Interest
OCIO Office of the Chief Information Officer
OCM Operational Configuration Management
ODBC Open Database Connectivity
ODC Other Direct Costs
ODL   Object Description Language 
ODNI Office of the Director of National Intelligence
ODOS Order Distribution and Order Status
ODS Order Distribution Service
OE Operations Engineer
OEI Office of Enterprising Information
OEM Original Equipment Manufacturer or Oracle Enterprise Manager
OFE Order Fulfillment Element
OGC Open Geospatial Consortium
OHS Order Handler Subsystem
OIRD Observatory Interface Requirements Document
OIS OLI-2 Interface Simulator
OITL Orbit-In-The-Life
OIV On-orbit Initialization and Verification
OJT On-The-Job Training
OLAP On-Line Analytical Processing
OLI Operational Land Imager
OLI-2 Operational Land Imager-2
OLTWG Old Landsat Technical Working Group
OM Operations and Maintenance
OMA  Oblique Mercator Type A 
OMB Office of Management and Budget or Oblique Mercator Type B
OMI Ozone Monitoring Instrument
OMP Operations Management Plan
OMS Optimum Management System
OO Orbit Oriented
OOB Out-of-Band
OPA Organizational Process Asset
OPeNDAP Open-Source Project for Network Data Access Protocol
OPM Office of Personnel Management
OPM3 Organizational Management Maturity Model
OPR Office of Primary Responsibility
O-PRB Operations Products Review Board
OPS   Operations 
Ops Con Operations Concept
Ops GUI Operations Graphical User Interface
OQPSK Offset Quadrature Phase Shift Keying
OR Operations Readiness
ORB Object Request Broker
ORR  Operations Readiness Review
ORT Operational Readiness Test
OS Operating System or OLI-2 Simulator
OSB Observatory System Branch
OSC Orbital Science Corporation
OSHA Occupational Safety and Health Administration
OSI  Open Systems Interconnection 
OSS Object Storage Server or Operations Support Simulations or Open Source Software
OSSMA Office of Systems Safety and Mission Assurance
OST Object Storage Target
OSTP Office of Science and Technology Policy
OTB Over Target Baseline
OTF Optical Transfer Function or OLI Test Facility
OTS OLI-TIRS Subsetter or Over Target Schedule or Off-The-Shelf
OUI   Operator User Interface 
OV Operational Verification
OV-1 Operational View 1
OVA Operations Validation and Acceptance
OVAD Operational Verification Acceptance Document
OVAP Operational Verification Acceptance Period
OWB Oracle Warehouse Browser or Oracle Warehouse Builder
OWSGUI Oracle Web Service GUI 

P

P&C Project Management and Controls
P&S Planning and Scheduling
P/D Programmable Demodulator
P/N Part Number
P/P Patch Panel
P3I Preplanned Product Improvement
PaaS Platform as a Service
PAC   Partial Aperture Calibrator or Prince Albert, Canada Ground Station
PAIV Project Acceptance and Implementation Variance
PAM Pluggable Authentication Module
PAN   Production Acceptance Notification or Panchromatic 
PAP Primary Archive Program
PAPH Pseudo-Average Pulse Height
PAPL Project Approved Parts List
PAR Post-Assessment Report
PASC   Partial Aperture Solar Calibrator 
PB Playback or Petabyte
PBL Project Baseline Log
PBS Project Breakdown Structure
PBTLM PB X-Band Housekeeping Telemetry
PC  Personal Computer or Polyconic or Production Control or Program Charter or Property Clerk
PCA   Physical Configuration Audit or Physical Channel Access or Point of Closest Approach 
Pcache Processing Cache
PCB Parts Control Board or Project Control Board
PCD   Payload Correction Data 
PCDS   Payload Correction Data Subsystem 
PCI Peripheral Component Interface
PCI-E or PCIe Peripheral Component Interconnect Express
PCI-X Peripheral Component Interconnect Extended
PCM Pulse Code Modulation
PCP Parts Control Plan
PCR Project Closeout Review
PCS   Process Control Subsystem or Product Control Subsystem or Production Control Subsystem
PCSS  Program Coordinate Systems Standards 
PCU Power Control Unit
PD Product Distribution or Position Description or Program Directive
PDA Personal Digital Assistant
PDB Program Decision Board or Project Database
PDD   Presidential Decision Directive 
PDF   Portable Document Format or Payload Data Formatter 
PDI Product Delivery Interface
PDL Product Design Lead
PDM Precedence Diagramming Method
PDPS Planning and Data Processing Segment 
PDR Product Delivery Record or Preliminary Design Review
PDRD   Product Delivery Record Discrepancy 
PDRM Product Delivery Receipt Mechanism
PDS  Product Distribution System 
PDU Protocol Data Unit or Power Distribution Unit
PED Personal Electronic Device or Portable Electronic Device
PER Performance Evaluation Review or Pre-Environmental Review
PERT Program Evaluation and Review Technique
PF Polarization Factor
PF1 Poker Flats 1
PFPA  Prime Focal Plane Assembly 
PFR Problem / Failure Report
PG Product Generation
PgC Program Charter
PgIMS Program Integrated Master Schedule
PgMP Program Management Plan
PGN Polar Ground Network
PGS Product Generation System (Generic Name for NLAPS) or Product Generation Subsystem
PgWBS Program Work Breakdown Structure
PHA Preliminary Hazard Analysis
PI Primary Investigator
PIA Project Implementation Agreement or Privacy Impact Assessment
PIB Payload Interface Board
PICS Pseudo-Invariant Calibration Site or Planetary Image Cartography System
PID Process Identification
PIE Payload Interface Electronics
PII Personally Identifiable Information
PIL Parts Identification List
PIMS Project Integrated Master Schedule
PIP Premium Internet Protocol
PIV Personal Identity Verification
PIXELQA Pixel Quality Assessment
PKI Public Key Infrastructure
PKO Project Kick-Off
PL Public Law
PL/SQL Procedural Language / Structured Query Language
PLA Payload Adapter
PLAR Postlaunch Assessment Review or Program Level Requirements Agreement or Program Level Requirements Appendix
PL-DRO  Phase-Locked Dielectric Resonance Oscillator 
PM Phase Modulation or Program Management or Project Management
PMB Performance Measurement Baseline
PMBOK Project Management Book Of Knowledge
PMC Performance Monitoring Counter or Program Management Council
PMEF Primary Mission Essential Function
PMI Project Management Institute
PMMM Program Management Maturity Model
PMO Persistent Mission Object
PMP Project Management Professional or Project Management Plan or Procurement Management Plan
PMPDR   Physical Media Product Delivery Record 
PMPDRD   Physical Media PDR Discrepancy 
PMRT Post-Mission Readiness Testing
PMSC Program Management Systems Committee
PMSEIT Program Management, Systems Engineering, and Integration and Test
PMT Performance Measurement Technique
PN  Pseudorandom Noise or Pseudo-Noise
PNG Portable Network Graphics
PNTR   Pointer 
PO Project Owner or Purchase Order
POA&M Plan of Action and Milestones
POC Point of Contact
POJO Plain Old Java Object
POL Policy
POP Point-Of-Presence or Point of Performance or Period of Performance
POS Position and Orientation System
POSC   Petrotechnical Open Software Corporation 
POSIX Portable Operating System Interface for Unix
PP Planning Package or Pull-Pin
PPF   Payload Processing Facility 
PPL Preferred Parts List
PPM Program Project Management
ppm Parts Per Million
PPOC Procurement Point of Contact
PPP Project Protection Plan
PPQA Process and Product Quality Assurance
PPR Post-Pass Report
PPS Pulse Per Second
PQ Pixel Quality
PR Program Review or Problem Report or Product Request or Purchase Request
PRA Paperwork Reduction Act or Probabilistic Risk Assessment
PRB  Problem Report Message 
PRD Project Reference Database
PRDS Project Reference Database System
PRI  Priority Mask Message 
PRISM Professional Resources in Information Systems Management
PRL Pull Remote Logs
PRN Pseudorandom Noise Pattern
PS   Polar Stereographic or Production Server
PSA Pre-Security Assessment
PSD Power Spectral Density
PSF Point Spread Function
PSG Pull and Send GPR
PSGUI Production Server Graphical User Interface
PSHSCCSS Percent Slope, Hillshade, Cloud, Cloud Shadow, and Snow
PSI PCS Startup IAS
PSK  Phase Shift Keyed 
PSLA Project Service Level Agreement
PSM Project Safety Manager
PSMON Power Status Monitor
PSR Priority/Service Request Mask File or Preship Review or Preshipment Review or Program Status Review
PSS Pull and Send SSOH
PSU Power Supply Unit
PSW1 Partial Surface Water 1
PTM Principal Task Manager
PTP Primary Transfer Program or Programmable Telemetry Processor
PTR Post-Test Review
PTS Project Task Structure
PUB Publication
PUP Perfectly Uniform Pitch
PV Planned Value
PVCS   Polytron Version Control System 
PVL   Parameter Value Language 
PWA Printed Wire Assembly
PWB Printed Wiring Board
PWBS Project Work Breakdown Structure
PWC PCS Work Order Controller
PWG PCS Work Order Generator
PWL PCS Work Order Scheduler Lite
PWS Project Website

Q

Q   Quadrature Channel 
Q&A   Quality and Accounting 
Q1 Quarter 1
Q1G L1G Quality Assurance
Q1R L1R Quality Assurance
Q2 Quarter 2
Q3 Quarter 3
Q4 Quarter 4
QA Quality Assurance or Quality Assessment
QAA   Quality Assurance Audit
QAS Quality Assessment Subsystem
QB Quality Board or Quality Band
QC Quality Control
QCM Quartz Crystal Microbalance
QFS Quick File System
QMM   Landsat Quarterly Management Meeting 
QMP Quality Management Plan
QMS Quality Management System
QOCI Qt Oracle Call Interface
QPSK   Quadrature Phase Shift Keying 
QUI Quality Assurance User Interface
QWIP Quantum Well Infrared Photometers
QWR  Quarterly Web Review 

R

R&D  Research and Development
R/T Receive/Transmit
R0C A stage of Radiometric Processing; Radiometric Calibration
R0R A stage of Radiometric Processing; Radiometric Artifacts Collection
R1 Release 1
R1R  A stage of Radiometric Processing; Cosmetic Changes
R21 Resource 21
R3 Release 3
RA Right Ascension or Risk Assessment
RAC Real Application Cluster or Risk Assessment Code
RAD Radiometric or Rapid Application Development
RADSATQA Radiometric Saturation
RadSim Radiometry Simulator
RAID Redundant Array of Independent Disks
RAM  Random Access Memory or Responsibility Assignment Matrix or Resource Allocation Matrix
RAMP Radarsat Antarctica Mapping Project
RAS Reliability, Availability, Serviceability
RBD Risk Based Decision
RBS Reflective Band Sensor or Risk Breakdown Structure
RBST Role-Based Security Training
RBV  Return Beam Vidicon 
R-C Resistor-Capacitor
RCA Radio Corporation of America
RCA-EO Requirements, Capabilities, and Analysis for Earth Observations
RCC Raw Computer Compatible 
RCM Resource Configuration Manager
RCN  Revision Control Number 
RCR Remote Controlled Repository
RCS Reaction Control System
RD Requirements Document
RDAC Redundant Disk Array Controller
RDB Requirements Database Baseline
RDBMS Related Database Management System
RDC Remote Desktop Connection
RDCS  Raw Data Capture Subsystem 
RDPS  Raw Data Processing Subsystem 
RDS  Raw Data Subsetter 
RDSS RCC Data Subsetter or Raw Data Subsetting Subsystem
RE Requirements Engineer and Responsible Engineer
REC Recovery Time
REF Reference
REL Relative
REQ Service Request Message or Requirement
REST Representational State Transfer
RF  Radio Frequency 
RFA Request for Action
RFC Request for Comments
RFI Request for Information
RFID Root File Identification
RFO Request for Offer
RFP  Request for Proposal
RFQ Request for Quote
RFR Request for Record or Run for Record
RFS Radio Frequency System
RG Relative Gain
RGB  Red Green and Blue Color Value 
RH Red-High or Right Hand
RHC  Right-Hand Circular 
RHCP Right-Hand Circularly Polarized
RHS Right-Hand Side or Right-Hand SLO
RHSS RHEL Satellite Server
RIDS Review Item Discrepancies
RIM Risk Information Management Tool
RIO Risks, Issues, and Opportunities
RIPL Risk Identification Prompt List
RIS24  24-bit Raster Image 
RITSO Regional IT Security Officer
RL Red-Low
RLN Resource Load Network
RLUT Response Linearization Look-Up Table
RM Requirements Management or Risk Manager or Resource Manager
RMAN Recovery Manager
RMB Risk Management Board
RMD Risk Management Database
RMF Risk Management Framework
RMM Risk Mitigation Maneuvers
RMP Requirements Management Plan or Risk Management Plan
RMR Risk Management Record
RMS Root Mean Square or Risk Management System
RMSE Root Mean Square Error
RMSEr Radial Root Mean Square Error
RMT Risk Management Tool
RN Random Noise
RO Receiving Officer
ROI Return on Investment or Region of Interest
ROIC Read-Out Integrated Circuit
ROLO Robotics Lunar Observatory
ROM  Rough Order of Magnitude 
ROS Relative Operational Sequence
RPC Remote Procedure Call or Rational Polynomial Coefficient
RPE Rational Publishing Engine
RPI Rumpin, Indonesia Ground Station
RPM Revolutions per Minute
RPS Radiometric Processing Subsystem 
RR Readiness Review
RRAS Routing and Remote Access Services
RRB Reduced Resolution Browse
R-S  Reed-Solomon
RSA Rivest-Shamir-Adleman
RSB Remote Sensing Branch
RSD Remote Sensing Division
RSDO Rapid Spacecraft Development Office
RSDP Rapid Spacecraft Development Office
RSPP Robotic System Protection Plan
RSR Relative Spectral Responses
RSS Reuse Subsystem or Really Simple Syndication or Rich Site Summary
RST Relative Time Sequence
RT Real Time
RTA  Roof Top Antenna 
RTC  Remote Telemetry and Command Unit 
RTCS  Relative Time Command Sequence 
RTF Rich Text Format
RtoO Research-to-Development-to-Operations
RTS Relative Time Sequence
RTT Round Trip Time
RTTM Requirements-To-Test Matrix
RVM Requirements Verification Matrix
RVPN Railroad Valley Playa
RWA Reaction Wheel Assembly
RX Receive

S

S&O  Search and Order
S/C  Spacecraft 
S/T Straight-Through
S/W Software
SA Spacecraft Analyst or Single Access or Systems Administrator or Storage and Archive Subsystem or System Architect
SA-AC Storage Archive – Archive Cache
SA-IC Storage and Archive – Internal Cache
SA-PC Storage Archive – Processing Cache
SAA South Atlantic Anomaly or Solar Azimuth Angle
SaaS Software as a Service
SAC  Satellite Application Centre (South Africa) 
SADD System Algorithm Description Document
SAFe Scaled Agile Framework
SAG System Administrator Guide
SAGUI Storage and Archive Graphical User Interface
SAIC  Science Applications International Corporation 
SAM  Scan Angle Monitor or Storage Archive Manager
SAMP Software Acquisition Management Plan
SAN Storage Area Network
SANS System Administration, Networking, and Security Institute
SAP Systems Applications and Products or Software Assurance Plan
SAPMSO Space Asset Protection Mission Support Office
SARR Security Assessment Response Report
SAS Serial Attached SCSI or Solar Array Simulator
SAT Site Acceptance Testing
SATA Serial Advanced Technology Attachment
SATO Science Algorithms to Operations
SAW Systems Analysis Workgroup
SBAF Spectral Band Adjustment Factor
SBC Single Board Computer
SBCG System Build and Configuration Guide
SBG Software Build Guide
SBM Serena Business Manager or Solutions Business Manager
SBRS  Santa Barbara Remote Sensing 
SBS Subsetter System
SBU Sensitive But Unclassified
SC Spacecraft or Science Campaign
SCA Sensor Chip Assembly or Snow Covered Area
SCAMA Switching, Conferencing, and Monitoring Arrangement or Station Conferencing and Monitoring Assembly
SCC Stress Corrosion Cracking or System Control Center
SCD Small Conversion Device
SCDR Spacecraft Critical Design Review
SCES Station Contract Execution Summary
SCH  Contact Schedule Message 
SCI Software Configuration Item
SCID  Spacecraft Identifier 
SCL  Signal Conditioning Unit - Lower Equipment Module 
SCM Software Configuration Management
SCN  Scan 
SCP  Standard Controls Processor or Secure Copy Protocol
SCR System Concept Review or Software Configuration Request or Standard Collection Request or Special Collection Request
SCS Scan-Correlated Shift or Satellite Checkout Station or NOAA/IPO Space and Communications Segment
SCSI Small Computer Software Interface
SCTR Special Calibration Test Requirements
SD South Dakota or Scan Direction
SDAT Special Data Acquisition Tool
SDD  Software Design Document
SDDS Seamless Data Distribution System
SDF  Software Development File 
SDLC System Development Life Cycle
SDLT  Super DLT 
SDM Silo Data Manager
SDMP Software Development Management Plan
SDN South Dakota Network
SDP  Software Development Plan or Science Data Production or Science Data Processing
SDPS Support Data Processing Subsystem or Science Data Processing Segment
SDR System Design Review
SDS  Scientific Data Set 
SDU Service Data Unit
SDVF Software Development and Validation Facility
SDW Seamless Data Warehouse
SE Systems Engineer or Systems Engineering
SEA Sensor Azimuth Angle
SEB Source Evaluation Board
SED  Software Engineering Department 
SEE Single-Event Effect or Science Execution Environment or Software Engineering Environment
SEI  Software Engineering Institute 
SEIT System Engineer Integration and Test
SEL Single-Event Latchup or Software Engineer Lead
SELC System Engineering Lifecycle
SelfDef Self-Defining CMDA format
SEM Security Engineered Machine
SEMP Systems Engineering Management Plan
SEO Systems Engineering Office
SET Systems Engineering Team
SEU  Single-Event Upset – Anomaly Event 
SEV Severity or Sun-Earth-Vehicle angle 
SEZ Sensor Zenith Angle
SF Service Framework
SFBME Short-Form Brouwer Mean Element
SFC Scene Framing Component
SFCG Space Frequency Coordination Group
SFFT Short-Form Functionality Testing
SFT SIFMT File Transfer
SFTP SSH File Transfer Protocol
Sg/SG6 Svalbard Ground Station
SGDAWG Space to Ground Data Acquisition Working Group
SGI  Silicon Graphics Incorporated or Shadnagar, India Ground Station
SGICD Space to Ground Interface Control Document
SGP4 Simplified General Perturbations
SGS Svalbard Ground Station or Svalsat Ground Station
SGT Stinger Ghaffarian Technologies
SH Southern Hemisphere
SHA Secure Hash Algorithm
Shapelib Shapefile Library
SHC Shutter Histogram Characterization
SHS  Second Half Scan 
SHSERR Second Half Scan Error
SI Searchable Inventory or Space Imaging or Science Instrument or Système International
SIAT Spectral Image Annotation Tape
SIC Spacecraft Identifier Code
SID Searchable Inventory Database or System ID
SIEM Security Information and Event Management
SIFMT Scene to Interval to File Mapping Table
SIG  Signaling 
SIP Standard Internet Protocol
SiPIN Silicon PIN
SIPS Science Investigation Processing System
SIR  Scientific Investigations & Research or Survey Investigation and Research
SIRCUS Spectral Irradiance and Radiance Responsivity Calibration Using Uniform Sources
SIRU Scalable Inertial Reference Unit
SIS Science Information System or Spacecraft Interface Simulator or Spherical Integrating Sources
SISO Subsystem Information System Owner
SISSE Senior Information System Security Engineer
SITL Single Interval-In-The-Life
SITP Software Integration Test Plan
SKMP System Key Management Plan
SL  Scan Line 
SLA Service Level Agreement or Scan Line Artifact
SLAM Storage Location Allocation Manager
SLAT Spacecraft Location and Attitude Tape
SLATE System Level Automation Tool for Enterprises
SLC Scan Line Corrector or Software Development Life Cycle
SLD  Scan Line Data 
SLI Sustainable Land Imaging
SLL  Scan Line Length 
SLO Scan Line Offset 
SLOC Standard Lines of Code
SLP Service Location Protocol
SLPP Summary Level Planning Package
SLS  Scan Line Start 
SM Schedule Manager or Scan Mirror
SM RVM Science and Mission Requirements Verification Matrix
SMA  Safety and Mission Assurance or S-Band Multiple Access
SMAP Safety and Mission Assurance Plan 
SMAT System, Model, and Analysis Tool
SMC Subsetter Monitor and Controllers
SMD Stored Mission Data or Science Mission Directorate
SME  Scan Mirror Electronics or Subject Matter Expert
SMP Software Maintenance Plan or Software Management Plan
SMR Staff Management Request
SMRD Science and Mission Requirements Document
SMS System Management Server
SMSR Safety and Mission Success Review
SN  Space Network 
SNAS Space Network Access System
SNMP Simple Network Management Protocol
SNR Signal-to-Noise Ratio
SNUG Space Network Users' Guide
SO Search and Order
SOA Service-Oriented Architecture or Satellite Operator Agency
SOAP Simple Object Access Protocol
SOC Satellite Operations Center
SOCC Satellite Operations Control Center
SOD Seconds Of Day
SOH State of Health
SOM  Space Oblique Mercator 
SON Statement of Need
SOO Statement of Objectives
SOP  Standard Operating Procedure 
SORN System of Record Notice
SOS Spacecraft/Observatory Simulator
SOW  Statement of Work
SP Special Publication
SPAOS Standard Product Automatic Ordering System
SPARC Scalable Processor Architecture
SPDR Spacecraft Preliminary Design Review
SPI Schedule Performance Index
SPIM SPOT Image
SPIT Systems Performance Improvement Team
SPITL Scheduling Period In The Life
SPL Software Project Lead
SPOC Service-Oriented Architecture (SOA) Proof of Concept or Security Point of Contact
SPOF Single Point of Failure
SPOT Satellite Pour l'Observation de la Terre (Satellite for Earth Observation)
SPR Software Problem Report
SPS Science Product System
SPSR System Preship Review
SPVM System Performance Verification Matrix
SPVP System Performance Verification Plan
SQA Software Quality Assurance
SQAP Software Quality Assurance Plan
SQL Structured Query Language
SQMS Software Quality Management System
SQPSK Staggered Quadrature Phase Shift Keying
SQRT  Square Root
SR System Review or Surface Reflectance
sr  Steradian 
SRAEROSOLQA Internal Surface Reflectance Aerosol Quality Assessment
SRB Schedule Review Board or Standing Review  Board
SRCLOUDQA Surface Reflectance Quality Assessment Band
SRD   System Requirements Document 
SRI Standard Robot Interface
SRLUT Spectral Radiance Look-Up Table
SRM Silo Resource Manager
SRO Systems Review Office
SRP Systems Review Plan
SRR System Readiness Review or System Requirements Review or Software Requirements Review or Specific Requirements Review
SRS Software Requirements Specification or System Requirements Specification
SRT Systems Review Team or Si Racha, Thailand Ground Station
SRTM   Software Requirements Traceability Matrix or Shuttle Radar Topography Mission
SRV SUBETTER_REQUEST_View
SS Space Segment or System Support or Signal Strength
SSA  S-Band Single Access or Space Situational Awareness
SSCL Standard System Control List
SSD Subsystem Design Document
SSERB Systems Support Engineering Review Board
SSG System Support Group
SSH Secure Shell
SSHGS Secure Shell Gateway Service
SSI Sensitive Security Information
SSIP System Safety Implementation Plan
SSL Secure Socket Layer
SSM Scene Select Mechanism or Scene Select Mirror
SSO Single Sign-On
SSoH Stored State of Health
SSOP Security Standard Operating Procedure
SSP System Security Plan or Satellite Support Plan
SSP-MSO Space System Protection - Mission Support Office 
SSPA  Solid State Power Amplifier 
SSPP Systems Safety Program Plan
SSR  Solid State Recorder or Software Specification Review
SSRR Spacecraft System Requirements Review
ST System Test or Surface Temperature
STC System Test Case
STD Standard
STDEV Standard Deviation
STDMP Simulated and Test Data Management Plan
STDN Spaceflight Tracking and Data Network 
STE System Test Equipment
STESR System Test Execution Summary Report
STF  System Transfer Function
STIG Security Technical Implementation Guide
STIM Stimulus
STK StorageTek or Systems Toolkit
STOL System Test and Operations Language
STP System Test Plan
STQA Surface Temperature Quality Assessment
STR System Test Report or Special Task Report
STS Scene Transmit Schedule
STSOC System Test and Operations Language
STSS Synchronize to Secondary Server
STV Spacecraft Transportation Vehicle
SUI Subsetter Operator User Interface
SUM Summary
SUN Sun Microsystems, Inc.
SV  Space Vehicle, Schedule Variance, or Subversion
SvalSat Svalbard Satellite Station
SVN Sun-Vehicle-Normal angle or Subversion
SVT Site Verification Test
SVVP System Verification and Validation Plan
SW Switch or Software
SWD Software Development
SWE Software Engineer
SWG Simulator Working Group
SWIR Short Wavelength Infrared or Shortwave Infrared
SWOT Strength, Weakness, Opportunity, and Threat
SZA Solar Zenith Angle

T

T Temperature 
T&A Trending and Analysis or Trending & Archive
T&C Telemetry and Command
T/V Thermal/Vacuum
T1 Tower 1
T2 Tower 2
T382 Triangular 382
TAI International Atomic Time
TAMR Telemetry Archive Metrics Report
TAP Technical Assessment Panel
TAR Tape Archiver
TAT Turn-Around-Time 
TB Terabyte
TBC To Be Confirmed
TBD To Be Determined 
TBR To Be Resolved or To Be Reviewed or To Be Refined
TBS To Be Submitted or To Be Supplied or To Be Specified or To Be Scheduled
TC Test Case or Test Conductor
TC0AOS TIRS Collection 0 Automatic Ordering System
TC1AOS TIRS Collection 1 Automatic Ordering System
TCDC Total Cloud Cover
TCP Transmission Control Protocol or Technology Control Plan
TCP/IP Transmission Control Protocol/Internet Protocol 
TCPI To Complete Performance Index
TCS Thermal Control Subsystem
TCXO Temperature-Compensated Crystal Oscillator
TD Test Director
TDEA Triple Data Encryption Algorithm
TDF Tracking Data Formatter or Time-Dependent Factor
TDI Time Delay Integration
TDMS Technical Data Management System
TDR Test Discrepancy Report 
TDRS Tracking and Data Relay Satellite
TDRSS Tracking and Data Relay Satellite System 
TDT Terrestrial Dynamical Time
TDY Temporary Duty
TE Test Engineer
TEM Technical Exchange Meeting
TERSS Tasmanian Earth Resources Satellite Station Consortium 
TESR Test Execution Summary  Report
TFA Two-Factor Authentication
TFDH Telemetry Frame Delivery Header
TFF TIRS Free Flyer
tHC The Hammers Company
TIC Trusted Internet Connection
TID Total Ionizing Dose
TIFF Tagged Image File Format 
TIM Technical Interchange Meeting or Technical Issue Memorandum or Thermal Infrared Module
TIPCE TIRS-2 Image Performance and Cryogenic Evaluation
TIR Thermal Infrared
TIRS Thermal Infrared Sensor or Thermal Infrared Scanner
TIRS-2 Thermal Infrared Sensor -2
TIS Thermal Infrared Sensor
TLE Two-Line Element 
TLM Telemetry
TLS Transport Layer Security
TM Thematic Mapper or Traverse Mercator or Task Manager or Test Modulator
TM-A Thematic Mapper - Archive Format
TM-R Thematic Mapper - Raw Format
TMACS Thematic Mapper and Multispectral Scanner Archive Conversion System
TMIAS Thematic Mapper Image Assessment System
TML Total Mass Loss
TMR Thermal Mapper Raw
TMS Training Management System
TMSR TSSC Monthly Status Report
TMSS TM Subsetter
TNOC Tromso Network Operations Center
TNOS Tromso Network Operations Centre
TNS Transport Network Substrate
TO Task Order or Terrain Occlusion
TOA Top of Atmosphere
TOA BT Top of Atmosphere Brightness Temperature
TOMS Total Ozone Mapping Spectrometer
TOR Terms of Reference
TP Task Plan
TPL Telemetry Packetization Layer 
TPM Technical Performance Measures
TPS Test Procedure Specification
TQCM Thermoelectric Quartz Crystal Microbalance
TRAD Thermal Radiance Layer
TRAM Tracking, Routing, and Metrics
TRAMAOS Tracking, Routing, and Metrics Automatic Ordering System
TRD Technical Requirements Document
TREES Tropical Ecosystem Environment Observations by Satellite
TRN Technical Redirection Notice
TRR Test Readiness Review
TRT Transition Readiness Test
TS TIRS-2 Simulator
TSI Honeywell Technology Solutions Inc.
TSR Technical Service Request
TSSC Technical Support Services Contract
TST Technical Support Team
TT Terrestrial Time
TT&C Telemetry, Tracking, and Control
TT&E Test, Training, and Exercise
TTF TIRS Test Facility
TTL Transistor-Transistor Logic
TTMS TSSC Task Management System
TTOR Transition To Operations Review
TTPs Tactics, Techniques, and Procedures
TURFTS TDRS Users RF Test Set
TUTR Tunable Universal Track Receiver
TVAC Thermal Vacuum
TWITL Total WRS-2 In The Life
TWM Task and Work Management
TWTA Traveling-Wave Tube Amplifier

U

U/C Up Converter
U/L Uplink 
U/P  Uplink Processor 
UAC User Account Control
UAF University of Alaska, Fairbanks
UAR Update as Required
UB Undistributed Budget
UDP Upper Data Point or User Datagram Protocol
UDT UDP Data Transfer
UG User's Guide
uhd User's Home Directory
UI  User Interface 
UIC User Interface Compile
UID Unique Identifier
UIS USGS Inventory Server
UL Upper Left 
ULA United Launch Alliance
ULC Update LGN Cache
UM Unified Messaging
UML Unified Modeling Language
UNEP United Nations Environment Programme
UNIX Bell Laboratories trademark for operating system language and time sharing
unixODBC Unix Open Database Connectivity
UP User Portal System
UPE User Portal Element
UPS Uninterruptible Power Supply or Universal Polar Stereographic
UPW User Portal Website
UQPSK Unbalanced Quadrature Phase Shift Keying
UR Upper Right or User Request
URAD Upwell Radiance Layer
URL Uniform Resource Locator 
URP User Request Parameters
URS User Registration System
US  United States 
USAF United States Air Force
USAID U.S. Agency for International Development
USB Universal Serial Bus
USC United States Code
USDA  U.S. Department of Agriculture 
USG U.S. Government 
USGS U.S. Geological Survey 
USML United States Munitions List
USNO U.S. Naval Observatory
USPS U.S. Postal Service
USSTRATCOM U.S. Strategic Command
UT  Universal Time or Unit Test
UT1 UTC Corrected 
UTC  Universal Time Code or Coordinated Universal Time
UTM Universal Transverse Mercator 

V

V&V Verification and Validation
VA Veterans Administration or Department of Veterans Affairs
VAC Variance at Completion or Volts AC
VAFB  Vandenberg Air Force Base 
VAL Validation
VAP Value-Added Processor
VAR Value-Added Resellers or Variance Analysis Report
VC Virtual Channel
VC63 Virtual Channel 63
VCA Virtual Channel Access 
VCDU Virtual Channel Data Unit 
VCID Virtual Channel Identifier or Virtual Channel Identification
VCLC  Virtual Channel Link Control 
VDD  Version Description Document 
VDP Validation Data Products
VER  Version 
VF Valley Forge 
VIIRS Visible Infrared Imager / Radiometer Suite 
VIS Visual Information Systems
VisID Visual Identification
VLAN Virtual Local Area Network
VLUT Vendor Look-Up Table
VM Version Manager 
VMM Virtual Machine Manager
VMS Virtual Memory Storage
VNIR Visible and Near Infrared 
VO Verification Owner
VOI Value of Information
VOIP Voice Over Internet Protocol
VPC Virtual Port Channel
VPN Virtual Private Network 
VQA Visual Quality Assurance
VRM Verification Requirements Matrix
VRP Video Reference Pixel
VRS Vertical Resampling Space
VSWIR Visible to Short Wavelength Infrared
VTL Verification Tracking Log
VTP Verification Test Procedures
VVP Verification and Validation Plan

W

W3C World Wide Web Consortium
WA Work Authorization
WAD Work Authorization Document
WAN Wide Area Network
WB  Wideband 
WBDR Wideband Downlink Report
WBM Wideband Module
WBS Work Breakdown Structure
WBV Wideband Video
WBVT Wideband Videotape
WC Worst Case
WCS Web Coverage Services
WDCD Wideband Data Capture Device
WELD Web-Enabled Landsat Data
WFS Web Feature Services
WG Working Group
WGCV Working Group for Calibration and Validation
WGS World Geodetic System or Wallops Ground Station
WGS84 World Geodetic System 1984
WILMA Wide Long-Term Multi-Satellite Archive
WIP Work In Progress
WITL WRS2-In-The-Life
WLS Weighted Least Square
WMO World Meteorological Organization
WMS Web Mapping Services
WMTS Web Mapping Tile Services
WO Work Order
WORS  Wallops Orbital Tracking Station 
WOTIS Wallops Orbital Tracking Information Systems 
WP Work Plan or Work Package
WPS Wallops Ground Station
WR Western Range
WRS Worldwide Reference System 
WRS-2  Worldwide Reference System-2
WRS2TT Worldwide Reference System-2 to Time Translation
WRS2TTT Worldwide Reference System-2 to Time Translation Table
WSC White Sands Complex 
WSDL Web Service Definition Language
WSGT White Sands (NASA) Ground Terminal 
WS-I Web Services Interoperability
WVTCS Wideband Videotape Conversion System
WWW World Wide Web 
WYSIWYG What You See Is What You Get

X

XIB Transmitter Interface Board
XML Extensible Markup Language 
XS Multispectral SPOT Sensor
XSD XML Schema Definition
XTX X-Band Transmitter 

Y

YGC Yaw Gyro Compassing 
YH Yellow-High
YL Yellow-Low
YSF Yaw Steering Frame
YTD Year-To-Date

Z

Zulu time (same as GMT) 
ZB Zettabyte
ZFS Zettabyte File System

0-9

0R Zero Reformatted Data
6H  Band 6 - high gain 
6L  Band 6 - low gain 
6S Second Simulation of a Satellite Signal in the Solar Spectrum