Gravimetric and Astrogeodetic Measurements at GPS Locations in Karakorum

Abstract

There exist an excellent distribution of gravimetric and astrogeodetic data in the northern part of the Indian platform, yet the region of the Karakorum sintaxis, of the Hindu Kush and of the Pamirs, comprising Northern Pakistan, NW India (Ladakh), China (Sinkiang) and bordering with Afganistan and the USSR has for decades had far less coverage. The first systematic explorations and mapping of Central Karakorum are due to Desio (1929) and to Shipton (1937–39). The first systematic gravimetric and astrogeodetic surveys of the same area are due to Marussi and collaborators, beginning 1954. In 1988, under the leadership of Prof. Ardito Desio and with the support of the Italian National Research Council we have extended north of the 36. parallel the gravimetric profiles and succeeded to establish two new astronomic stations at high altitude, using GPS for the determination of the geodetic coordinates on a geocentric ellipsoid. We report on our activity and, merging our data with those given by Marussi, the Survey of India and others, as well as using global geoidal models, we discuss the basic features of the geoid in this area.