Nowadays the GPS measurements are one of the most frequently used technique in geodesy. With this technique ellipsoidal height can be reckoned. However in the engineering practice orthometric heights (height above sea level) are used. The orthometric heights are determined by levelling. Transforming the GPS-derived ellipsoidal heights to orthometric heights it is important to know the distance ...

SUMMARY The fast development of Global Positioning System (GPS) technology provides more precise and rapid surveying in geodetic applications than the traditional terrestrial positioning techniques. Therefore, considerable savings on time, labour and cost are achieved by GPS measurements. The geometric height supplied by GPS is ellipsoidal height and it needs to be transformed to orthometric he...

A GPS satellite survey was carried out with the Macrometer to support construction at the Stanford Linear Accelerator Center (SLAC). The network consists of 16 stations of which 9 stations were part of the Macrometer network. The horizontal and vertical accuracy of the GPS survey is estimated to be l-2 mm and 2-3 mm respectively. The horizontal accuracy of the terrestrial survey, consisting of ...

The need to determine accurate heights relative to the North American Vertical Datum of 1988 (NAVD 88) is more prevalent today than ever before. Projects are no longer isolated unto themselves, or designed in a box. Due to global and regional issues such as the environment, and municipal planning, the need to represent the topographic features of the earth accurately in three dimensions is of p...