Accession Number:

AD0276746

Title:

ELECTRONIC CORRELATION TECHNIQUES FOR CHANGE DETECTION

Descriptive Note:

Corporate Author:

PHILCO CORP BLUE BELL PA

Personal Author(s):

Report Date:

1962-02-17

Pagination or Media Count:

1.0

Abstract:

Several alternative electronic-correlation techniques to detect significant change in repeatcover aerial photography are considered. The most promising techniques are shown to involve analyzing each photograph for its local significance before attempting detection of change. Success in distinguishing significant from trivial change appears directly related to ability to first analyze significance. A particular system organization is developed based on cross-correlation of transformed, abstracted, and spatially quantized representations of the photography called feature maps. Through simulation on the Philco 2000 computer, the system is shown effective in detecting the appearance or disappearance of man-made structures while ignoring changes in shadowing andor minor misregistrations. Desired improvements in detailed system logic are discussed. To maximize utility, the change-detection equipment should be supported with automatic rectification equipment and an image-information storage and retrieval system that automatically locates the repeat-cover images in the library and aligns them with the new photographs for analysis. Candidate systems to perform these supporting functions are reviewed and evaluated. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE