Studies And Applications Of GPS Leveling Optimizing Software

Since 80 s last century,GPS leveling is one of the hot point of GPS application research.Replace traditional leveling measurement with GPS leveling,labor,consumption,expenditure can be decreased a lot,working efficiency can be improved greatly,digital city,digital area and digital earth can be provided with effective data collection means.With GNSS technology' spread,making GPS leveling technology widespread is more forceful currently.Now the widespread process of provincial quasi-geoid refining still rely on simple GPS leveling fitting to correct systematic errors and it isn't suitable to small areas.The improvement and reasonable evaluation of the result about the method of GPS leveling fitting is important and necessary in the application of GPS leveling.Based on this engineering background,this paper implements systematic research on the matters that GPS leveling fitting users care,programs fitting-optimization software and makes engineering practice.The main achievements and conclusions of this paper are listed as follows:1.Polynomial integral fitting method,Hardy multi-surface function method,mobile interpolation method and corresponding methods that introduce gravitational field model have been analyzed and summarized deeply,new way to optimize the fitting method is offered,and those methods are chose as improvement objects of optimization method.2.Research on the vertical level that GPS leveling fitting can reach is made,according to the leveling specification,a new evaluation method is offered and corresponding formulas are deduced.This method capitalizes on the GPS known leveling point information,and solves the questions that users care reasonably.3.Research and offer optimization process of three traditional GPS leveling fitting methods,especially the polynomial integral fitting optimization method,in order to choose the optimized coefficient combination,the mathematical test is introduced to testify model's suitability,the disadvantage of plain suitability about the plane method,quadric method and three surface method is avoided,choosing point manually is avoided,the automation of polynomial integral fitting method is achieved.4.The design principle of GPS leveling fitting optimization software has been provided,according to this principle,some ac hievements has been made,such as optimizing software interface,designing function,designing data document structure and designing software code,GPS leveling fitting optimization software(GPSL2.0)that owns graphic user interface,complete function and easy to expand is achieved in the end,and it is fundamental to the application of GPS leveling fitting.5.Combined with three practical engineering,and with the GPS2.0,some conclusions reference are listed as follows: a)three methods would be identical when points is evenly distributed in surveying area,surveying area is regular such as retangular and manual factors are choozed appropriately;b)Hardy method would be superior than others when the shape of surveying area is looked like zone;c)Moving interpolation would be superior than others when the shape of surveying area is irregular and there are more GPS-leveling poins in the area;d)the results of the optimizing method with EGM2008 gravitational field model mustn't be superior than others,which needs to be studied in future.6.GPSL2.0's application reference has been provided.Because there are the least optional factors among three methods,polynomial integral fitting optimization method could be used first to provide referenes for other metods to choose their optional factors.