Measurements of glacier motion and deformation are obtained by automat
ically matching features, such as crevasses, on repeat images. A compu
ter-based method identifies and tracks groups of features on successiv
e images, and calculates their displacement, and the rotation and dist
ortion of the ice. Ice deformation within each matched area is permitt
ed and calculated using a least-squares method within each area. The m
ethod is applied to SPOT satellite images of ice stream B, Antarctica.
A quality-checking scheme rejects inappropriate matches. The results
compare satisfactorily with velocities obtained by manual methods from
repeat photography of the same region. A simpler version of the metho
d, similar to that used by Bindschadler and Scambos, also obtains very
satisfactory results.