LAUSR

Bistatic synthetic aperture radar (SAR) is a new type of SAR system which is capable of achieving multi‐angle target detection and flexible configuration. For spaceborne bistatic SAR, when operating at low frequencies, it is susceptible to the ionosphere. The ionospheric Faraday rotation effect will cause a rotation of polarisation plane of electromagnetic waves, leading to amplitude and phase errors between different polarisation channels of SAR. This effect can be compensated by estimating the Faraday rotation angle. Currently, Faraday rotation angle estimation methods for spaceborne SAR are all applicable to monostatic SAR. However, due to the different signal propagation paths between bistatic SAR and monostatic SAR, the Faraday rotation angle estimation method differs for bistatic SAR. This paper proposes a Faraday rotation angle estimation method for bistatic spaceborne SAR, which is applicable to the alternating bistatic mode. The effectiveness of the method is verified through simulation experiments and the performance of the method is analysed. Under different signal‐to‐noise ratios (SNR) and filtering window sizes, the estimation error range is 0.02°‐0.26°.