Evaluation of BAQ on Tiangong-2 interferometric imaging radar altimeter data compression

Abstract

Tiangong-2 Interferometric imaging radar altimeter (InIRA) applies the technology of small incident angle and high precision interferometric phase measurement, which has the characteristics of wide swath, imaging and high accuracy height measuring. Compared with traditional altimeter, InIRA can realize much wider swath and can obtain SAR image of observed area, so there is a high requirement of onboard memory and downlink speed for InIRA. As a result, we need to investigate data compression technique for InIRA to reduce the data rate. As an efficient algorithm for SAR echoes data compression, Block Adaptive Quantization (BAQ) is widely used to spaceborne SAR system for raw data compression. The motivation of this work is to evaluate the influence of BAQ algorithm on interferometric coherence and sea surface height error for InIRA.