Incorporation of Flow Stripes as Constraints for Calibrating Ice Surface Velocity Measurements from Interferometric SAR Data

Abstract

Derivation of absolute surface velocities from interferometric SAR data requires velocity control points, and rock outcrops or in situ GPS measurements are commonly utilized as velocity control points in the calibration of model parameters. However, it is often difficult or costly to acquire sufficient number of such velocity control points for the model calibration. This paper introduces ice flow stripes as alternative control points for the calibration of interferometric SAR data. Acquisition of this type of flow direction control points is relatively easy and inexpensive. We have derived the observation equations for the flow direction control points and formulated the least squares adjustment problem for calibrating the surface displace measurements respectively derived from the conventional interferometric method and speckle tracking method. Our experiments with Radarsat interferometric SAR data in Antarctica demonstrate that the exploitation of ice flow stripes as control points are effective, practical, and economical.