Study On Differential GPS Landslide Displacement Monitoring System

In recent y ears, accompanied by global clim ate change and crus talmovement abnormalities, the frequency and damaged degree of various types ofgeological disaster were increased significantly, which have caused a large num berof casualties and economic loss in the whole world. In China, landslide hazards weremost widely distributed and occur most frequently, the damage from which was alsovery serious. So, doing a better job of lands lide disaster prevention and reduction hasthe great significance.In carrying out prevention and treatment of the landslide, we can take hold of thesituation in terms of landslide deformation through a dynamic monitoring analysis oflandslide displacement, and it also can provide the scientific basis for the forecast ofthe disaster. Although the current method for landslide displacement monitoring ofmany, but each has its advantages and di sadvantages, or because the sy stemcomplicated, costly, practicality is low; or because the scop e of application is sm all,real time low, which is dif ficult to app ly to autom ated real-time landslidedisplacement monitoring. By comparing several comm on methods of landslidedisplacement monitoring, and combined with the advantages of GPS measurem ent,on the basis of the study of principle of GPS positioning, GPS positioning errors andcarrier phase difference m ethod, aiming at the practical circumstances of landslidedisplacement monitoring, this article designed a set o f long-range real-timedifference GPS short baseline lan dslide displacement monitoring system with thelow-price single frequency GPS-OEM card fo r measuring core. In th is system, thebase station and mobile station were placed in monitoring site to form a short baselinemeasurement and eliminate the public errors better, so as to reach the low cost andhigh accuracy m easurement result. Adopting GPRS and Inte rnet communicationmethod, it can transmit the observation data from monitoring site to monitoring centerin time, and increase the perform ance of system. In addition, upper computer writes the baseline solution programs with VC++and realizes the remote visual monitoring,so as to improve the scope of application.This work includes: the study of principle and error processing method of GPSpositioning; the study of carrier phase differential positioning technology; t heresearch of dynamic calculation method of integer ambiguity; choosing the suitableGPS receiver and antenna; the research of the original data analysis method; designremote short baseline la ndslide monitoring programme; design of data acquisition,transfer, and hardware circuit; preparation of baseline solution PC software.The landslide displacement monitoring system that designed in the thesis, on theone hand realize the lo w cost and high accu racy by the short baseline m easurementmode, and realize remote real-time monitoring combined with GPRS communicationon the other hand. But the cycle slip of the system should also be considered in thepractical application, so detection and reparation for cycle slip is the next focus of thestudy; more research is needed to solve th e problem that the la rge interference inrainy weather.