Digital Raster Graphics (DRG) Data Dictionary

  

 

Cooperator

• Field Definition:  This field identifies the co-operating members involved with this data.

 

Coordinates - Decimal Degrees

• Field Definition:  The latitude and longitude are provided in decimal degrees for the following fields:

          Values:

          Scene Center Latitude and Longitude

         Northeast (NE) Corner Latitude and Longitude

         Northwest (NW) Corner Latitude and Longitude

         Southeast (SE) Corner Latitude and Longitude

         Southwest (SW) Corner Latitude and Longitude

 

         Latitude Format Decimal Degrees: -90.000 through 90.000

         Longitude Format Decimal Degrees: -180.000 through 180.000

 

         Number of decimal places will vary by dataset – check collection in EE.

 

Coordinates - Degrees, Minutes, Seconds

• Field Definition:  The latitude and longitude are provided in degrees, minutes, and seconds for the following fields:

          Values:

          Scene Center Latitude and Longitude

          Northeast (NE) Corner Latitude and Longitude

          Northwest (NW) Corner Latitude and Longitude

          Southeast (SE) Corner Latitude and Longitude

          Southwest (SW) Corner Latitude and Longitude

          Longitude Format:

          DDDMMSS.SSH

          DDD = Degree(s) with a range of 0 through 180

          MM = Minute(s) with a range of 0 through 59

          SS.SS = Second(s) with a range of 0 through 59.99

          H = Hemisphere with E for east and W for west

 

          Latitude Format:

          DDMMSS.SSH

          DD = Degree(s) with a range of 0 through 90

          MM = Minutes(s) with a range of 0 through 59

          SS.SS = Second(s) with a range of 0 through 59.99

          H = Hemisphere with N for north and S for south

 

Coordinate System

• Field Definition:  Code indicating the coordinate system used when capturing the digital information.

 

Create Date

• Field Definition:  Creation date of the product.

          Values:

          Format:

          YYYY = Year

          MM = Month

          DD = Day

 

Digitizer

• Field Definition:  A reference to persons or organizations who perform digitized work.

 

Entity ID

• Field Definition:  This field is used to uniquely identify data which can be ordered in any combination of unique products.

          Example:

          Entity ID: DT00001062457

          Where:

          DT = Data Set Identifier

          0000 = Filler

         1062457 = ODBPRODID

 

Horizontal Datum

• Field Definition:  A geodetic reference for horizontal control. Five quantities are known: latitude, longitude, azimuth of a line from the point, and two constants that are the parameters for the reference ellipsoid (NAD83, NAD27).

 

Mapcat ID

• Field Definition:  This number is assigned for internal NMD use only.

 

Map Name

• Field Definition:  7.5 minute quadrangle mapname. 15 minute quadrangle mapname. 30x60 minute quadrangle mapname. 1x2 degree quadrangle mapname.

 

Map Type

• Field Definition:  This field refers to the kinds of maps, their classifications and their systems of measurement.

          Valid Code:

          TF = TOPOGRAPHICAL FEET

 

Number of Columns

• Field Definition:  The number of pixel columns from left to right on the map.

 

Number of Rows

• Field Definition:  The number of pixel row from top to bottom on the map.

 

Product ID

• Field Definition:  This number is assigned for internal NMD use only.

 

Version Number

• Field Definition:  The version number is based on the cell ID and the product group. If only one product exists per cell id/product group, the version value is 1. The higher the version number the newer the data is.

 

Pixel Resolution X

• Field Definition:  Measure of the sharpness of an image or feature.

 

Pixel Resolution Y

• Field Definition:  Measure of the sharpness of an image or feature.

 

Product Group

• Field Definition:  This field describes a specific type of data.

          Values:

          Valids:

          221 = 7.5x7.5-MIN DRG

          248 = 30x60-MIN DRG

         443 = 7.5x15-MIN DRG

         444 = 7.5x7.5-MIN DRG ORTHOPHOTO MAP W/O IMAGERY

         445 = 7.5x7.5-MIN DRG ORTHOPHOTO MAP

         446 = 1x2-DEGREE DRG

         466 = 15-MIN DRG

         980 = 7.5x7.5-MIN DRG-FOREST SERVICE SINGLE EDITION

         1040 = 1x3-DEGREE DRG

         1120 = 1x4-DEGREE DRG

         1121 = 2x1-DEGREE DRG

         1122 = 4x20-DEGREE DRG

         1123 = 4x28-DEGREE DRG

         1124 = ANTARCTICA DRG

 

Scale

• Field Definition:  This field refers to the distance of on a map and the corresponding distance on the earth.

          Valid Codes:

          20,000

          24,000

          25,000

          30,000

          63,360

          100,000

          250,000

 

Source Date

• Field Definition:  Original map generation date.

 

Standards Version ID

• Field Definition:  Information on the processing steps used to create digital raster graphics. Detailed information on the Standards Version specifications can be found in the USGS National Mapping Program's Standards for Digital Raster Graphics.

 

State

• Field Definition:  Two character state abbreviation.

 

Status Type

• Field Definition:  "H" stands for Historical (revised by a newer version) data and "A" stands for Recommended current data.