CAFTS – A COHERENCE AND FEATURE TRACKING STUDY FOR SENTINEL-1

摘要

Temporal decorrelation is a major problem whenrnapplying repeat pass interferometry or coherentrnfeature tracking techniques to ice and snowrnsurfaces as it significantly reduces the amount ofrnviable data. This study was performed to assess thernlevel of coherence measured between SAR imagernpairs with a 6 and 12-day temporal baseline, in linernwith the planned repeat cycles of Sentinel-1 (S-1).rnBased on this, an assessment was made about thernproportion of S-1 data that will be suitable forrnmeasuring ice velocity. Analysis showed highrnlevels of coherence over the ‘exposed rock’ landrncover type, with 75.5% of data from the 12-dayrnimage pairs remaining above the 0.7 coherencernthreshold. High levels of coherence were measuredrnfrom 3 and 6-day image pairs over the ‘ice sheet’rnand ‘ice stream’ land surface types however, overrn12-days just 42.5% and 19.1% of data remainedrnabove the 0.7 coherence threshold respectively.rnThis highlights the importance of utilising the S-1rn6-day repeat period for obtaining sufficientlyrncoherent data over snow and ice land cover types.