Large DEM of Delta Junction, Alaska
Guritz, R.M., O.S. Lawlor, T. Logan, J. Miller, and R.B. White
Alaska SAR Facility, Geophysical Institute, University of Alaska Fairbanks

Researchers at the Alaska SAR Facility (ASF) have created rectified, map-projected Digital Elevation Models (DEMs) from 15 pairs of ERS tandem mission SAR images using a fully automated interferometric DEM generation procedure. Since the release of our first Interferometric SAR (InSAR) prototype in 1996, significant enhancements have been implemented which automate the process: sub-pixel registration in half the time, election of seed-points from USGS DEMs, and georectification of resulting DEMs to a map projection. Althouth DEM "holes" from the Goldstein branch-cut phase unwrapping algorithm limit out ability to determine scene baselines precisely, all frames have average area elevation errors of less than 5 meters and geolacations accurate to the meter level. Analysis of the height maps shows pointwise RMS elevation errors below 10 meters. Moreover, the automated implementation of our technique results in excellent alignment between image frames. Overall, our results demonstrate large-scale, automated DEM production using InSAR techniques, and the results can be more accurate than existing DEMs in many areas.