NUPO Research Activities

Science Center Objects

NUPO's research efforts support the strategic implementation of UAS within the USGS and the DOI.

Efforts focus on platform evaluation and the integration of new innovative sensors, the recommendation of UAS data collection best-practices, development of processing techniques for data products, and establishment of data quality and accuracy standards. Research missions, often performed in cooperation with other DOI bureaus and non-DOI collaborators, serve as vital tools in these evaluation and integration activities and helps establish UAS's effectiveness to support specific earth science investigations.

Platform Evaluation
Secretarial Order 3379 imposed an indefinite grounding on “Designated UAS,” which included the current fleet of DOI sUAS platforms, with limited exceptions for emergency response and associated emergency preparedness. In the memo, “Important Update on Secretary’s Order 3379 and Blue Small Unmanned Aircraft Systems”, released October 6th, 2020, sUAS platforms approved under the Department of Defense Defense Innovation Unit’s (DIU) Blue sUAS Initiative were made exempt from this order, i.e., classified as “Non-Designated UAS.” NUPO will evaluate the approved sUAS platforms from this list that can be operated on non-military frequencies to determine what DOI data collection needs they can support. NUPO is also working on the platform specifications needed to carry heavier mapping sensors in hopes that DIU’s Blue UAS effort will address and approve a larger sUAS platform.

Sensor Integration
NUPO is responsible for sUAS platform sensor integration with oversight by the DOI’s Office of Aviation Services (OAS). Sensors being integrated include high-resolution visible-spectrum cameras, metric mapping cameras, multispectral and hyperspectral cameras, high-definition video cameras, ground penetrating radar systems, Light Detection and Ranging (LiDAR) scanners, geomagnetometers, radio telemetry devices, gas emission, and particle detection sensors. Sensor integration efforts include evaluating and testing the various sUAS payloads in the field as proof-of-concept research projects.

Research into 3D printing technologies support efforts to create customized sUAS sensor mounts of high structural quality that can increase the mounts' durability. Techniques and patterns for the rapid prototyping of these engineered components, i.e., mounts and brackets, are being developed and the use of 3D printing for customized weather stations is being investigated. NUPO is also looking into the creation of hollow 3D sensor copies that can be appropriately weighted and used to eliminate the possibility of loss or damage to expensive sensors during integration test flights.

Data Collection 
Another research activity at NUPO is development of the best-practices and data standards needed to achieve high-quality UAS derived spectral and structural geospatial data products. Evaluation of the high-resolution and low-altitude data acquired from sUAS-mounted sensors is being used to establish recommendations for data collection, data processing, and ground control referencing to aid accuracy assessment and verification.  UAS LiDAR quality assurance and quality control efforts are being validated by combining UAS collected data with a Global Navigation Survey System (GNSS) survey quality base station, Propeller AeroPoints, and vertical GPS LiDAR reflector points for three-dimensional ground control and vertical height assessments. Protocols are being developed for collecting ground-truth spectral measurements using field-based portable spectrometers.  Accuracy assessments are also taking place on a wide range of lower-cost spectrometers. 

Data Processing Techniques
NUPO develops and implements leading-edge data processing techniques utilizing UAS derived high-resolution imagery to generate geospatial products with centimeter-level accuracies. Radiometric calibration software tools are also being developed to support UAS derived image calibration and best-practices for scientific analysis. Radiometric calibration, the process of converting image pixels to meaningful physical units such as reflectance, is a critical step when utilizing sUAS collected imagery for scientific research. NUPO’s radiometric calibration efforts include developing, testing, and enhancing UAS RadCal, a software toolbox for sUAS multispectral data processing.  Investigates into various calibration target options, such as tarps and rigid panels, for optimal performance and robustness are being performed in the field.  And NUPO is documenting the protocols for collecting ground-truth spectral measurements using multiple types of spectrometers and maintains an updated source of radiometric calibration references and resources to support DOI scientists.

Geospatial Data Standards
Data standards are written and updated as new sUAS compatible sensors are tested and verified.  For example, the YellowScan VX-20 LiDAR scanner lists a 1 cm level of precision (at one standard deviation) and 2.5 cm of network accuracy; these specifications are then validated with either data acquired during actual flights or based on unique stand-alone tests. Once verified, these specifications can be used to generate the metadata associated with USGS sUAS published data releases. 

As newer GNSS receivers are being marketed, NUPO is analyzing their GNSS survey data to outline their strengths and limitations in support of UAS data validation.  Various GNSS correction methods are also being evaluated based on specific technological advancements including NOAA’s Online Positioning User Service (OPUS), Trimble RTX, Propeller AeroPoints Correction Network, MakeItAccurate.com, and NASA JPL GispyX.