Validation of ICESat-2 Data along CHINARE Route in East Antarctica

NASA launched the Ice, Cloud, and Land Elevation Satellite-2 (ICESat-2) satellite on September 15, 2018. The photon counting altimeter of ICESat-2 is designed to provide centimeter-level accuracy surface elevation observations and is expected to reduce the uncertainty of the estimated sea level rise contribution from Antarctica. The ICESat-2 mission team has conducted a validation campaign and stated that the data released in the first year met the design requirements. In this study we designed and implemented an independent validation scheme along the 36^th CHINARE (Chinese Antarctic Research Expedition) route in East Antarctica as a different validation site. 1) GNSS data collected during a week in December 2019 along the 500-km traverse from the Zhongshan Station to the Taishan Station are compared with the crossover ICESat-2 points. The GNSS receiver (CHC i70) was fixed on the roof of the Pisten Bully Polar 300 and cooperated with 5 GNSS base stations spaced every ~100 km. 2) To investigate photons reflectivity we used a rectangular area target for each site at three Chinese stations, with considerations of the reflectivity and satellite tracks. 22 upward-looking optical prisms were installed to capture photons with known ground elevations. 3) Finally, we utilized DJI Phantom 4 unmanned aerial vehicles (UAVs) to obtain centimeter-level DEMs of ice sheet surface and compare with the ICESat-2 points. The results are analyzed for several applications and compared against the published validation results of the mission team.