Open AccessNon‐uniform phase filter for Tiangong‐2 Interferometric Imaging Radar Altimeter
Author(s) -
Dong Xiao,
Zhang Yunhua
Publication year - 2019
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2019.0430
Subject(s) - interferometric synthetic aperture radar , remote sensing , interferometry , geodesy , radar altimeter , altimeter , geology , synthetic aperture radar , radar , coherence (philosophical gambling strategy) , digital elevation model , elevation (ballistics) , shuttle radar topography mission , radar imaging , optics , computer science , physics , mathematics , geometry , telecommunications , quantum mechanics
The interferometric imaging radar altimeter (InIRA) on‐board Chinese Tiangong‐2 space laboratory is a Ku‐band interferometric radar whose major aim is to measure the wide‐swath ocean topography. Unlike traditional interferometric synthetic aperture radar (InSAR) aiming at measuring digital elevation model of land surface, Tiangong‐2 InIRA adopts small incidence angles and short baseline to get strong and high coherency reflections from ocean surface. The interferometric phase noise is a notable source of errors which limits the accuracy of the ocean height measurements. Compared with traditional InSAR, the height error of Tiangong‐2 InIRA shows different distribution pattern due to the absolutely small but relatively large variation incidence angles. This study gives a filtering method for interferometric phase generated with small incidence angles and short baseline. Non‐uniform windows are selected according to the relation between the coherence, imaging geometry, and the height variation. Results on Tiangong‐2 InIRA data are analysed by comparing the non‐uniform filtering method with traditional multi‐looking method.