Resolution analysis for geostationary spaceborne-airborne bistatic forward-looking SAR

Abstract

Owing to the spatial separation of transmitter and receiver, bistatic SAR is able to image the area in front of the moving direction of transmitter or receiver, but the geometry model is more complex than that of monostatic SAR, which brings great difficulties to system design and imaging process. Besides, the special geometry configuration of geostationary spaceborne-airborne bistatic forward-looking SAR results in non-orthogonal and non-uniform ground resolution, which is not considered in the traditional range and azimuth resolution. To solve this problem, the resolution ellipse based on the generalised ambiguity function (GAF) is used to maintain the best and worst ground resolution in the resolution cell. The receiver's flight direction is designed to obtain the optimal uniform ground resolution distribution, which has great value for system design and the receiver's path planning. Finally, the accuracy of the resolution ellipse and correctness of the deduced formulas are verified by simulation.

Keywords

• spaceborne radar
• radar resolution
• path planning
• airborne radar
• radar imaging
• geometry
• synthetic aperture radar
• geometry model
• transmitter
• moving direction
• spatial separation
• resolution analysis
• optimal uniform ground resolution distribution
• receiver
• resolution cell
• worst ground resolution
• generalised ambiguity function
• resolution ellipse
• azimuth resolution
• traditional range
• nonuniform ground resolution
• SAR results
• special geometry configuration
• imaging process
• system design
• great difficulties
• monostatic SAR