Abstract
Spaceborne microwave radiometer observations play vital roles in surface parameter retrievals and data assimilation, but widespread radio-frequency interference (RFI) signals in the C-band channel result in a lack of valuable data over large areas. Establishing repaired data based on existing observation information is crucial. In this study, Advanced Microwave Scanning Radiometer (AMSR)-2 C-band data affected by RFI were accurately repaired through the iterative principal component analysis (PCA) method in 2016 over the U.S. land area. The standard deviation (STD) and bias characteristics of the brightness temperature in the C-band vertical polarization channel were compared and analyzed before and after the restoration to verify the assimilation application prospect of the repaired data. Not only was the spatial continuity of the microwave imager observations significantly improved following restoration; the STD and bias of the observation minus background (OMB) of the restored data were basically consistent with those of the RFI-free data. The STD of OMB exhibited obvious seasonal variations, which were approximately 4.0 K from January to May and 3.0 K from June to December, whereas the biases were near zero in winter but negative (approximately −2.0 K) in summer. The surface type and terrain height also critically affected the STD and bias. The STD decreased with increasing terrain height, whereas the bias exhibited the opposite trend. The STD was largest in low-vegetation areas (4.0 K) but only approximately 2.0–3.0 K in pine forest and brush areas. These results show that the restored data have a high prospect for retrieval application and assimilation, and the STD and bias estimation results also provide a reference for land-based AMSR-2 data assimilation.
Funder
National Key R&D Program of China
National Natural Science Foundation of China
Youth Project of the National Natural Science Foundation of China
Natural Science Foundation of Jiangsu Province
FengYun-3 meteorological satellite engineering ground application Project
Subject
General Earth and Planetary Sciences
Reference56 articles.
1. Kachi, M., Imaoka, K., Fujii, H., Shibata, A., Kasahara, M., Iida, Y., Ito, N., Nakagawa, K., and Shimoda, H. Status of GCOM-W1/AMSR2 development and science activities. Proceedings of the SPIE-The International Society for Optical Engineering.
2. Soil moisture retrieval from AMSR-E;Njoku;IEEE Trans. Geosci. Remote Sens.,2003
3. Vegetation Water Content Retrieval by Means of Multifrequency Microwave Acquisitions From AMSR2;Santi;IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens.,2017
4. Tang, Y.H., and Zhang, W.J. Land surface temperature retrieval using amsr-e data in the central tibetan plateau. Proceedings of the 2016 IEEE International Geoscience and Remote Sensing Symposium.
5. Dai, L., Che, T., Xie, H., and Wu, X. Estimation of Snow Depth over the Qinghai-Tibetan plateau based on AMSR-E and MODIS data. Remote Sens., 2018. 10.
Cited by
1 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献