PRELIMINARY COHERENCE ASSESSMENT OF GAOFEN-3 SAR DATA

Gaofen-3 (GF-3) is the only in-orbit civilian SAR satellite of China. The satellite is specially designed for ocean observation. The coherence is not exclusively considered during satellite designing phase. In this paper, we conduct the preliminary coherence assessment of GF-3 SAR data. Decoherence sources of GF-3 consists of seven components. Baseline decoherence, signal-to-noise decoherence as well as the volume decoherence affects the coherence severely. While the last four components, i.e., volume decoherence, ambiguity decoherence, Doppler spectral decoherence and processing decoherence contributes to the coherence values slightly. We select 13 pairs of GF-3 SAR data and analyze the coherence. Results of the selected data show that the coherence values after multi-looking, flattening, elevation phase removal and filtering exceed 0.4 even at the dessert regions, making it potential in InSAR related applications such as DEM generation and deformation monitoring.