Paper Info
Title
Preliminary Significant Wave Height Retrieval From Interferometric Imaging Radar Altimeter Aboard The Chinese Tiangong-2 Space Laboratory
Abstract
The interferometric imaging radar altimeter (InIRA) aboard the Chinese Tiangong-2 space laboratory is the first spaceborne imaging radar working at low incidence angles. This study focuses on the retrieval of significant wave heights (SWHs) from InIRA data. The retrieved SWHs can be used for correcting the sea state bias of InIRA-derived sea surface heights and can supplement SWH products from other spaceborne sensors. First, we analyzed tilt, range bunching and velocity bunching wave modulations at low incidence angles, and we found clear dependencies between the SWH and two defined factors, range and azimuth integration, for ocean waves in the range and azimuth directions, respectively. These dependencies were further confirmed using InIRA measurements and collocated WaveWatch III (WW3) data. Then, an empirical orthogonal SWH model using the range and azimuth integration factors as model inputs was proposed. The model was segmented by the incidence angle, and the model coefficients were estimated by fitting the collocation at each incidence angle bin. Finally, the SWHs were retrieved from InIRA data using the proposed model. The retrievals were validated using both WW3 and altimeter (JASON2, JASON3, SARAL, and HY2A) SWHs. The validation with WW3 data shows a root mean square error (RMSE) of 0.43 m, while the average RMSE with all traditional altimeter data is 0.48 m. This indicates that the InIRA can be used to measure SWHs.
Year
DOI
Venue
2021
10.3390/rs13122413
REMOTE SENSING
Keywords
DocType
Volume
Tiangong-2 space laboratory, interferometric imaging radar altimeter (InIRA), significant wave height (SWH), empirical model, retrieval
Journal
13
Issue
Citations 
PageRank 
12
0
0.34
References 
Authors
0
5
Name
Order
Citations
PageRank
Lin Ren1153.15
Jingsong Yang21712.82
Xiao Dong300.68
Yongjun Jia401.01
Yunhua Zhang500.68