Research of Data Transformation for Super-totalstation Positioning System Integrated by GPS and Totalstation

Based on the discussion of the characteristics of GPS and totalstation,this paper focuses on the integration and data transformation for them.How to get the most precise three-dimensional cartesian coordinates of the station occupied by a totalstation through GPS unit integrated in it is emphasized,and then they are transferred to the local two-dimensional plane coordinates and the orthometric height by a series of mathematical models.The GPS unit,totalstation,radio,notebook computer and the corresponding software work together to form a new surveying system,super-totalstation positioning system(SPS) and a new surveying model for terrestrial surveying.With the help of this system,the positions of detail points can be measured at the same time with the station's.This will be a more advanced surveying type than pure GPS or totalstation model. GPS and totalstation are the two widely adopted surveying systems.GPS has the benefits that the line of sight between stations needn't to be sighted through and the measured distance may be very long.It has become the first considered method for establishing national,district or engineering project control networks.As for densely built urban area,the signal from the GPS satellite is severely interrupted by buildings around the station,especially for detail surveying,GPS is limited,then totalstaion will has its advantage to catch detail points in this case.But we have to set up a series of control points used as stations and back sight reference points to locate other unknown detail points for the later method based on totalstation.If there is no control point around the surveying area,the surveyor has to develop a control network from some known points far away from the considered area,so a heavy extra control surveying task is appended.The integrated GPS and SPS is a solution for the above problem.First,a GPS receiver and a radio is put on a reference station with known coordinates and good condition to receive GPS satellite signal.Then a totalstaion with built-in GPS unit is set up at any interest as well as with good condition to receive satellite signal point and oriented to another known point previously determined by SPS or GPS only.Last,the detail points are located by horizontal direction,slope distance and zenith angle.At the same time the GPS unit is recording the phase,poseudo range and navigation data from GPS satellites.So the station and detail points can be determined at the same time. We do some research work on SPS.The radio communication and data processing including baseline vector resolving,WGS84 cartesian coordinates to local system transferring,detail points measuring etc.have been designed.This paper is a description of our realized part of data transformation for SPS.