Design And Implementation Of A Portable Leveling Data Acquisition And Processing System

In recent years, the development of the geodetic surveying method, and especially the wide application of the satellite positioning technology have revolutionized the traditional theory and method of geodetic surveying. Traditional geodetic surveying is likely to be replaced by the satellite positioning technology. However, the geometrical leveling, as a kind of old methods, cannot be replaced by modern space technology totally in accurately passing elevation and constructing height control network.At present, the geometrical leveling is the only way to survey high accuracy leveling. There are a lot of geometrical leveling instruments, such as bubble type precise level, automatic level, digital level and assorted invar alloy leveling staff.Along with economic and social development, digital level is applied more and more extensively in surveying and mapping units. Compared to traditional optical level, it has many advantages:objective reading, high accuracy, fast speed, high efficiency, easy manipulation, and its data can be inputted directly into computers. It also has a disadvantage which its data cannot be used as the final results unless processed further. Its raw observation data which recorded by data recording program of the instrument has several types, because different manufacturers define different data structures.With practical experiences and production requirements in the surveying and mapping unit, the research contents of this paper are as follows:1. Analyzed and compared frequently-used means and methods of height measurement, including geometrical leveling, trigonometric leveling, GPS altimetric survey, the physical height measurement, to prove the necessity of geometrical leveling.2. Studied wireless communication methods of portable devices (such as PDA, mobile phone) and the Leica DNA03digital level. In the actual measurement, the existing system uses the wired connection between handbook and instrument, which is inconvenience.3. Designed a portable system for leveling data acquisition and processing, including PDA data acquisition system, PC data processing and adjustment system.4. Tested the practicability of this system combined with the actual project.