DIGITAL MAPPING ASSOCIATES
PHOTOGRAMMETRY SERVICES
Photography·Scanning·Triangulation·DTM·Contour Generation
Planimetrics·DEM·Digital Ortho Photography
MicroStation/AutoCAD/GeoPAK/GIS/MrSid/JPEG2000/TIFF formats
DBE Certifications in Oklahoma, Kansas, Missouri,
New Mexico & Texas
Why use Photogrammetry for your Survey?
Photogrammetry has been around for many years, and while the accuracy professional land survey crews may provide is second to none, the vertical exaggeration viewed through stereoscopic images allow photogrammetrists to collect Digital Terrain Data that field crews would not normally pick up in the field. The use of the floating measuring mark oriented to targeted location coordinates (provided by professional land surveyors) through various orientation and analytical triangulation processes prepare for the measurement of topographical survey data to be obtained efficiently and effectively for engineering design purposes.
DMAs approach to Photogrammetric Survey
Dependent on the scope of work, flight paths and target layout maps are prepared to meet the desired accuracy of your project. This requires minimal field survey of selected target locations, and with the use of Airborne GPS, the number of target locations may be reduced by more than fifty percent. The areas of heavy tree cover or areas where the ground is obscured will require additional field surveys, as well as, underground utilities/drainage structures and utility verifications.
Flight missions are scheduled upon the completion of target placements and permitting weather conditions. The next process is editing and labeling film to check for proper forward and side overlap, scanning of film diapositives follows film editing unless the flight mission obtains imagery using a digital mapping camera. Analytical triangulation then adjusts the photography to ground coordinates, permitting collection of topographic map data in requested coordinate system and leveling/layering schemes. Digital ortho photography can also be developed from DEM/DTM data collection and referenced to collected topographic map data or plotted as a scaled photo quality image.
