The Effects of Photo Characteristics upon Location Determination in a Photogrammetric Facility.

摘要

The operator of the Army Analytical Photogrammetric Positioning System (APPS) must perform a critical step in the coordinate determination procedure by the subjective comparison of dissimilar images. He must correlate reconnaissance mission imagery with aerotriangulated photographic stereoscopic pairs, known as data base imagery, and visually identify the image position on the data base of a target detected on the mission image. Results obtained from 40 image interpreters performing this task using vertical, oblique, and panoramic mission imagery are given. Two levels of target position difficulty were established: (1) A-points located at terrain or man-made features mutually identifiable on both mission and data base imagery; (2) B-points remote from terrain or man-made features mutually identifiable on mission and data base imagery. Transfer of A-points for vertical, oblique, and panoramic photographs was accomplished with good accuracy--median location error was 19 meters or less. Performance was significantly better when A-points in panoramic missions were located in the near-vertical half of the image in contrast to the near-horizon half. Transfer of B-points was more difficult. For vertical missions, median location error was about 20 meters. For oblique or panoramic imagery, location errors were markedly greater when the B-points were located in the horizon half of the image as compared to performance when the points were in the near-vertical half of the image.