STEREO-TERRESTRAL-PHOTOGRAMMETRY FOR HIGHWAY RESEARCH

THE MOVEMENT OF LANDSLIDES IS BEING STUDIED BY PLOTTING TOPOGRAPHIC MAPS OF SLIDE AREAS FROM PHOTOGRAPHS TAKEN WITH A TERRESTRIAL STEREO CAMERA SYSTEM. TOPOGRAPHIC MAPS MAY ALSO BE COMPILED BY THE USE OF METRIC-QUALITY TERRESTRIAL STEREO PHOTOGRAPHS AND APPROPRIATE STEREOPLOTTERS. THE STEREO PHOTOGRAPHS PROVIDE A PERMANENT RECORD OF THE POSITIONS OF THOUSANDS OF POINTS IN THE SLIDE AREA. A SINGLE MAPPING OF A HALF-ACRE SITE CONTAINING A LANDSLIDE WAS ACCOMPLISED WITH ABOUT ONE HALF HOUR OF TIME ON SITE OF A THREE-MAN FIELD PARTY, TAKING THE STERO PHOTOGRAPHS WITH ABOUT EIGHT HOURS OF WORK OF AN OPERATOR ON THE ZEISS TERRA- GRAPH STEREO-PLOTTER. THE SAME TERRESTRIAL STEREOPHOTOGRAM- METRIC MAPPING SYSTEM ALSO PROVIDES THE OPPORTUNITY TO QUICKLY RECORD THE PHYSICAL CIRCUMSTANCES RESULTING FROM VEHICLE ACCIDENTS. A NUMBER OF POLICE DEPARTMENTS IN EUROPE USE THIS TERRESTRIAL PHOTOGRAMMETRIC SYSTEM FOR COLLECTING INFORMATION ABOUT ACCIDENTS.