Key Technology Discussion on Surveying and Mapping 1:1000 Photogrammetric Digital Topographic Map of Laicheng Industrial Zone in Laiwu City

Taking use of VirtuoZo's digital photogrametric workstations of Supresoft Inc., employing full digital aerophotogrammetric mapping method, according to existing aerial photographic image database, at the foundation of basic control survey, we carry out aerial photographic control survey, surveying and mapping with pile point method, digital aerotriangulation and full digital stereocompilation. When taking 1:1000 topographic map obtained by indoor edition to field work for compration, supplement and regulation, we mainly aim at the following purposes: determining the nature and quantity as well as filling vacancy for ground and land features obtained by indoor stereocompilation; positioning for habitation, wall and railing, incompletely surveyed, drop shadow-covered and trees-obstructed ground features, as well as newly-added planimetric features after aerial photogrammetry; especially measuring the solid width of a house to centimeter and making eaves correction after measuring the length of a house when needed; correcting the geomatric positioning relationand of ground features according to their solid shape and fairly drawing them in the map; afterwards, we carry out graphic edition again during indoor work. Only in this way can we guarantee the horizontal and vertical accuracy of large scale photogrammetric mapping.