Bandwidth Considerations for Interferometric Applications Based on TanDEM-X

Abstract

For present and next-generation spaceborne synthetic aperture radar (SAR) missions the use of always larger bandwidths, higher pulse repetition frequencies (PRFs), and multiple acquisition channels is being required. Among the numerous parameters characterizing a SAR system, the specific range and azimuth bandwidth, selected for the SAR image formation, are of primary importance, since they directly affect the quality, the resolution, and the accuracy of the derived products. The purpose of this paper is to investigate their influence with particular focus on interferometric SAR (InSAR) applications. Exploiting the well-known relationships available from SAR theory, the impact of the range and the azimuth bandwidths on the coherence and on the interferometric phase errors is evaluated by means of simulations based on typical TanDEM-X acquisition scenarios. Some examples from real TanDEM-X data are provided as well. The results discussed in this paper can be used as recommendation for those who want to apply for a TanDEM-X science acquisitions proposal, exploiting the high commanding flexibility of the TanDEM-X system, and represent a valuable input for all users dealing with interferometric SAR data and for the design of future InSAR systems in general.