Abstract
Geosynchronous synthetic aperture radar (GEO SAR) has the potential for conducting long-term observation of target zones, which is essential for remote sensing applications such as disaster monitoring and vegetation measurements. The squint imaging mode is crucial for long-term observation using GEO SAR. However, this type of SAR imaging is problematic because the squint mode introduces a nonzero range cell walk, which increases the prevalence of invalid data in echoes and intensifies the coupling between the azimuth and range. Therefore, this paper proposes a novel squint mode GEO SAR imaging method based on the correction of the bulk range walk of received signals. Adjusting the starting time of the receiving window significantly reduces the redundancy in echoes. Then, first-order filtering, range cell migration correction, range compression, partial dechirp, and azimuth compression are used to obtain the imaging result. Simulation results for the GEO SAR imaging of Wenchuan County in China demonstrate that the proposed algorithm can achieve a resolution of 5 m within a 30 × 30 km swath over 48% of the orbital period.
Highlights
Geosynchronous synthetic aperture radar (GEO SAR) operates on an inclined orbit at a speed of nearly 3.075 km/s and at a height of approximately 35,786 km [1,2]
The present study focuses on squint mode strip-map GEO SAR imaging
We proposed a novel squint mode GEO SAR imaging method, where the bulk range walk is first corrected on receive by adjusting the starting time of the receive window and applying first-order filtering, RCM correction (RCMC), range compression, partial dechirp, and azimuth compression to obtain the focused single looking complex (SLC) image
Summary
Geosynchronous synthetic aperture radar (GEO SAR) operates on an inclined orbit at a speed of nearly 3.075 km/s and at a height of approximately 35,786 km [1,2]. Compared with low earth orbit (LEO) SAR, GEO SAR moves more slowly and has a wider field of view that is nearly one-third of the earth’s surface [3]. These features enable GEO SAR to observe target zones for a much longer period than LEO SAR, which is beneficial for conducting disaster monitoring [4]. This mode is composed of several strip-map observations acquired with different squint angles, and the target zone is imaged according to the overlapping area of the strip-map data received. Broadside SAR imaging, and squint mode SAR imaging, must be used to process echoes acquired by this observation mode
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
