简介:ThemainobjectiveofthisstudyistoimprovethegeoidbyGPS/levelingdatainEgypt.ComparisonsofthegravimetricgeoidwithGPS/levelingdatahavebeenperformed.OnthebasisofagravimetricgeoidfittedtoGPS/levelingbytheleastsquaremethod,asmoothedgeoidwasobtained.Ahigh-resolutiongeoidinEgyptwascomputedwitha2.5′×2.5′gridbycombiningthedatasetof2600originalpointgravityvalues,30″×30″resolutionDigitalTerrainModel(DTM)gridandthesphericalharmonicmodelEGM96.ThemethodofcomputationinvolvedthestrictevaluationoftheStokesintegralwith1D-FFT.ThestandarddeviationofthedifferencebetweenthegravimetricandtheGPS/levelinggeoidheightsis±0.47m.ThestandarddeviationafterfittingofthegravimetricgeoidtotheGPS/levelingpointsisbetterthan±13cm.InthefuturewewilltrytoimproveourgeoidresultsinEgyptbyincreasingthedensityofgravimetriccoverage.
简介:摘要:GPS是全球定位系统,具备较强的三维导航与定位功能,连续性、全球性、全能性优势显著,且保密性、抗干扰性良好。GPS技术被广泛应用到城市测量、航空测量等工程中。本文主要介绍GPS控制网设计相关问题,仅供参考。