An interactive technique to generate digital elevation data using a vidicon cameraA technique is proposed for the semi-automatic digitization of topographic maps using a vidicon camera interfaced with a mini-computer system. The required input is a black and white map that shows only contour lines and corresponding elevation values such as the advance prints of 7.5 minute USGS topographic sheets. A set of image processing algorithms is implemented on an image of the contour map acquired by a vidicon camera. The system developed performs extraction of contour lines, tagging elevation values and subsequent interpolation of elevations to produce, in 5 sec. x 5 sec. intervals of latitude and longitude, digital elevation matrices. The interpolation of elevations for non-contour points is achieved using a steepest descent algorithm. A communications capability allows the final data to be transferred over telephone lines to an off-site unit such as the floppy disk or a micro-computer.
Document ID
19860035965
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Sircar, J. K. (Maryland Univ. College Park, MD, United States)
Ragan, R. M. (Maryland, University College Park, United States)