The Research On Combined Adjustment Methods Of GPS And Total Station Data

Recent years, GPS and Total Station have been the two most popular means in surveying fields. Using in conjunction with the two instruments becomes a widespread reality. It is an important and urgent matter that achieving combined adjustment.For hybrid network using GPS and Total Station simultaneously, the traditional process method is stepped adjustment:GPS network data is adjusted firstly, then making total station data adjustment based on it. During the process, it regards the GPS adjustment result as true value, without error. But in fact, it’s not the case, the GPS position error will affect the result of the plane network surveyed by total station as original error. Based on the coordinate system transformation model, this dissertation attempt to unify the GPS baseline vector with the plane measurement data and completes all of the adjustment one-time. It can eliminate the original data errors of gradual adjustment primarily in this way.During the gradual adjustment process, the control network of different level set its weight and distributes its accident error independently. The method adopts combined adjustment, taking the observations from different level network as different type observations and unifying the weight and distribution of accidental error by adjustment random model, such as Helmert Variance components estimates. The combined adjustment distributes the accidental error more reasonable and evaluates precision more objective.On the engineering projects, the combined adjustment is conducted on the Gauss plane most of time. Therefore, the way to deal with the distortion of projection becomes to be a key link in the data processing. On the basis of fundamental, the forward projection formula is expanded to nine. Meanwhile, the Multivariate nonlinear function Newton iterative method is introduced into projection inverse formula. Consequently, the precision of Gauss projection is improved.At last, software which applies to the combined adjustment of GPS and Total Station observation data on Gauss plane is written using Visual C#.