Effect of random phase error and baseline roll angle error on eddy identification by interferometric imaging altimeter

• Published in: Journal of oceanology and limnology Vol. 40; no. 5; pp. 1881 - 1888
• Main Authors: Gao, Le, Sun, Hanwei, Qi, Jifeng, Jiang, Qiufu
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.09.2022; Springer Nature B.V; CAS Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences and Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China; Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266237,China%Beijing Radio Measurement Institute,Beijing 100854,China%CAS Key Laboratory of Ocean Circulation and Waves,Institute of Oceanology,Chinese Academy of Sciences and Center for Ocean Mega-Science,Chinese Academy of Sciences,Qingdao 266071,China
• Subjects: Abnormalities; Altimeters; Altimetry; Data analysis; Data processing; Detection; Earth and Environmental Science; Earth Sciences; Eddies; Empirical analysis; Error analysis; Interferometry; Low pass filters; Malformations; Ocean circulation; Oceanic eddies; Oceanography; Orthogonal functions; Phase error; Random errors; Satellites; Sea surface; Spacecraft recovery; Vortices; interferometric altimetry; error removal strategy; theoretical and systematic simulation; baseline error; random error; ocean eddy
• ISSN: 2096-5508; 2523-3521
• DOI: 10.1007/s00343-020-0044-3

To achieve better observation for sea surface, a new generation of wide-swath interferometric altimeter satellites is proposed. Before satellite launch, it is particularly important to study the data processing methods and carry out the detailed error analysis of ocean satellites, because it is directly related to the ultimate ability of satellites to capture ocean information. For this purpose, ocean eddies are considered a specific case of ocean signals, and it can cause significant changes in sea surface elevation. It is suitable for theoretical simulation of the sea surface and systematic simulation of the altimeter. We analyzed the impacts of random error and baseline error on the sea surface and ocean signals and proposed a combined strategy of low-pass filtering, empirical orthogonal function (EOF) decomposition, and linear fitting to remove the errors. Through this strategy, sea surface anomalies caused by errors were considerably improved, and the capability of satellite for capturing ocean information was enhanced. Notably, we found that the baseline error in sea surface height data was likely to cause inaccuracy in eddy boundary detection, as well as false eddy detection. These abnormalities could be prevented for “clean” sea surface height after the errors removal.