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.
