Comparing Applanix SmartBase and PP-RTX Processing Modes for Generating Smoothed Best Estimate Trajectories for NEON Airborne Missions
Abstract
The National Ecological Observatory Network (NEON) Airborne Observation Platform (AOP) generates 29 remote sensing data products derived from Lidar, RGB Camera, and Hyperspectral Imagery data products across 81 sites spanning different eco-climatic zones in the United States. The Smoothed Best Estimate Trajectory (SBET), used for geo- locating all AOP data products is a first step in the aerial data processing and is critical for ensuring accurate temporal analysis of NEON ecological data . NEON currently processes the SBETs using Applanix POSPac SmartBase , providing the most accurate trajectory data . However, this processing mode requires setting up a base station within 20 km of the site flown and is operationally expensive . Applanix also offers a PP-RTX ( POSPac Trimble Post-processed CenterPoint ® RTX™) processing mode which claims to provide a similar level of accuracy without requiring external GPS base stations. Since NEON has collected aerial data sets over multiple years and across the United States, a study was performed to compare SBET generated from these two modes. This study included data from all of our sites flown between 2016 to 2019, totaling over 500 SBETs. The absolute accuracy was assessed by comparing vertical accuracy over Nominal Runway calibration flights in Colorado, as well as number of sites spanning the US, where GPS ground validation points were also collected. Initial results from this analysis show that the average vertical difference between SBETs is typically < 5 cm, but can differ by up to 10-20 cm. Certain areas in the US exhibit higher mean difference in SBETs, such as the Desert Southwest, Alaska, and Tenessee. Further investigation is required to assess the trade-off of expense versus accuracy. AOP envisions using a hybrid approach of processing SBETs using SmartBase and PP-RTX to optimize accuracy and efficiency for our airborne collections.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMG005.0006H
- Keywords:
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- 1223 Ocean/Earth/atmosphere/hydrosphere/cryosphere interactions;
- GEODESY AND GRAVITY;
- 1229 Reference systems;
- GEODESY AND GRAVITY;
- 1241 Satellite geodesy: technical issues;
- GEODESY AND GRAVITY;
- 1243 Space geodetic surveys;
- GEODESY AND GRAVITY