USE of GPS in geodetic networks

Monitoring crustal deformation is very essential for constructionfield because the deformations may cause damage for some structures thatcan not overcome these deformations. Monitoring deformation processrequires the establ ishment of geodetic networks cover the area of interest,the deformations are determined by comparing the coordinates of stationsof these geodetic networks along successive epochs of observations, theepoch interval depends on the deformation source and the nature of thedeformable object.The conventional geodetic techniques used for determiningdeformations depend on obtaining the horizontal and vertical coordinatesof the monitoring networks from the geodetic measurements (horizontaland vertical angles, distances and height differences). The intervisibility,the atmospheric conditions and the distances between stations constrainthe optimization of these geodetic networks.The global positioning system GPS provides advanced and precisepositioning technique that satisfy the required specifications of the reliablemonitoring networks where great parts of the errors can be eliminated orgreatly reduced using dual frequency receivers and triple and doubledifference approaches.The coordinates of stations of the monitoring networks arecomputed relative to a number of reference stations which should be far..