1987 Volume 26 Issue Special1 Pages 25-35
Two Landsat scenes observed from two neighboring PATHS include a side-lap area located between the two scenes. Landsat data seen by each different angle from the two PATHS enable to compute elevation data of the side-lap area. A test site located in a side-lap area and including a high mountain area was selected, and a method to compute elevations of the test site was developed using two system corrected Landsat TM data which observed the test site from two neighboring PATHs. A base plane for computing elevation was assumed in the test site and two Landsat images of the test site seen from two different angles were overlapped on the base plane. Corresponding points between the two overlapped images were searched automatically throughout the test site and each satellite position at the moment of observation of the each corresponding point between the two lmages was computed from estimating data of satellite position used at the time of system correction. The elevation of the corresponding point was computed by finding the nearest point between two lines of sight drawn from each satellite position to each corresponiing point. An error (rms) of elevation computation method developed by this study was 117m which was examined at about 60 points selected for evalution of elevation computation accuracy, and it was improved to 93m by computing more precisely with an interpolation in searching corresponding points. An image of elevation data of the test site was generated automatically and it is evaluated by comparing with a counter map extracted from geographical maps of the test site. It was found that the both corresponded prettey well.
