Sar Repeat-pass Coherence in Winter for Boreal Forest Applications. a First Comparison between Asar and Jers-1 Sar

This paper presents the first comparison between repeat-pass coherence from ASAR and JERS-1 SAR. To reduce the influence of temporal decorrelation, repeat-pass pairs acquired during the winter season have been selected. ASAR 35day coherence and JERS-1 44-day coherence from six different test areas in Siberia and northern Europe have been evaluated. The results indicate that the decorrelation is more severe for ASAR coherence than for coherence from JERS-1. Only one of the five studied ASAR pairs shows coherence levels that are high enough to contain information that can be useful for forest applications. More ASAR pairs will be acquired during the current winter season. For most of the included JERS-1 pairs, the coherence is high enough to provide useful forest information. An example of growing stock volume estimation from one of the test areas shows a potential application.