Application Research Of SRTM Data In Electric Power Survey

The electric power survey technology keeps developing along with the development of surveying instruments and methods. In the wake of developments in GNSS(Global Navigation Satellite System) and line aerial photogrammetry, aerial line photogrammetry mode which is completely different with the conventional line measuring mode has currently become a mainstream. Especially in accompanied by many high precision global DEM data appears, using Google Earth, Global Mapper and a series of GIS software as a platform, the planning and design of transmission line including line route optimization, avoiding the influence of transmission line route, section data extraction, span measurement, tower position, statistics of across substance and so on. Operation mode of transmission line survey can be said to be changing with each passing day, which is a new attempt of traditional photogrammetric model. Especially in the application of Global Mapper platform, it loads many different DEM data to extract transmission line center section and both of left and right edge line section points. Based on three kinds of free and open global digital elevation data which are SRTM DEM, X-band SRTM DEM and ASTER GDEM, profile linear extraction function is applied to extract transmission line section point fast and conveniently. With the development of the data interface software, it is converted into the data format which can be identified by SLCAD software (overhead transmission line flat section map processing and positioning CAD system), and finally generated section map for tower placed pile field lofting. Through the practical application in Qinghai-Guoluo 1 10kV project, the SRTM data is investigated to be conformed with the standard line precision requirements, and the reliability of data quality, data accuracy, error and improved methods is analyzed. It is combined with the measured data to correct the elevation data. We believe that with the open of more high precision WorldDEM data, electric power survey will usher in great change. It is worth to look forward to space measurement instrument development and perfection of the satellite data. In the future, most line measuring problem can be solved only in indoor. And it would be possible that calibration tower and accident risk at the construction site only needs portable handheld terminal equipment.