In-orbit Calibration and Validation of HY-2B Altimeter Using an Improved Transponder

HY-2B (Haiyang) is the follow-on mission to HY-2A, Chinese first sea satellite for oceanography, launched in October 2018. The main payloads onboard are similar HY-2A. For altimeter, an in-orbit calibration mode was designed achieve higher precision. An improved transponder built and deployed campaign. purpose of this article describe validation altimeter based on transponder. A signal-rebuilt developed employed HY-2A calibration. It played important role quantitative analysis data products. a newly added, built. has some advantages over previous one rebuilt signal forms modulation ways. Two campaigns were carried out, April 2019 2020 at different sites. In two campaigns, precision range obtained less than 1 cm. further assessment result, comparison between Jason-3 performed terms surface height tens cross track points open ocean. result shows high degree accuracy stability instrument. China's next five-year plan (2021–2025), many more transponders related facilities would be installed ocean fields, serving variety altimetry missions.