Reconstruction of Coherent Pairs of Synthetic Aperture Radar Data Acquired in Interrupted Mode

Kurzfassung

A number of SAR systems might work in interrupted operation for different purposes. Examples are cooperative bistatic SAR systems with a synchronization link between transmitter and receiver, or multi-static systems operating in receive-only mode, among others. As a direct consequence, the acquired raw data contain missing echoes presented in a periodical or random pattern. Since the missing raw data introduce artifacts in the processed images, recovery methods have to be applied. Usually, spectral estimation-based interpolators can be used to recover data. Although such algorithms show good performance for point-like targets, their efficiency is decreased for distributed scatterers. In this paper we propose, for a coherent pair of SAR images, the use of the common information in one image to reconstruct the other and vice versa. The conditions required for the proper use of the approach are discussed and the method is verified using simulated data. One special case of study is the TanDEM-X mission, where the cooperative nature of the bistatic operation requires the periodic exchange of information between the satellites in order to gather information for calibration and synchronization creating a periodic missing data pattern in the raw data. For this case of study the reconstruction methods based on spectral estimation are analyzed and the proposed reconstruction using cross-information is validated.