Derivation of glacier velocity from SAR and optical data with feature tracking

Monitoring temperate glacier activity has become more and more necessary for economical and security reasons and as an indicator of the local effects of global climate. The most studied variable in ice dynamics in the literature is ice velocity. From remotely sensed images, mainly two types of methods have been used for the estimation of glacier flow velocities: feature tracking and differential interferometry (DInSAR). In this paper velocities of the Keqikaer glacier are acquired from ALOS (Advanced Land Observing Satellite) optical and SAR data respectively with feature tracking. We show that different window size in correlation calculation of feature tracking leads to different flow field. We also developed a new method to determine the best window size, and the method is testified by the two kinds of data.