Determination of the geoid with a high accuracy is the main task among researchers in the geodetic community. Precise determination of a regional geoid is usually carried out combining a global geopotential model data with a set of point or mean terrestrial gravity anomalies measured in the region and some topographic information. In this research a primary Iranian gravimetric geoid model has b...

Geoid modelling for India is a complex, exhaustive and continuous task because of its large area and tremendous varieties of surface. This paper reviews available geoid models for Indian Territory developed through geometric, gravimetric and hybrid methods for Northern, Eastern, Southern, and Western regions and presents a summary of further scope for the geoid development in India.

The Earth’s long-wavelength geoid anomalies have long been used to constrain the dynamics and viscosity structure of the mantle in an isochemical, whole mantle convection model. However, there is strong evidence that the seismically observed large low shear velocity provinces (LLSVPs) in the lower mantle underneath the Pacific and Africa are chemically distinct and likely denser than the ambien...

[1] We investigate the effects of lateral viscosity variations (LVVs) on mantle circulation model predictions of the global geoid. The present study is motivated in part by earlier findings that LVVs due to stiff slabs in the lower mantle have a strong influence on the geoid, and that slabs in the lower mantle are perhaps no stronger than the ambient mantle. However, more recently, it has been ...

The geoid is the fundamental surface that defines the figure of the Earth. It is approximated by mean sealevel and undulates due to spatial variations in the Earth's gravity field. The use of the geoid in regional geophysics is illustrated for the North-West Shelf of Australia by removing long-wavelength geoid features, due predominantly to deep-Earth mass anomalies, in order to reveal near-sur...

A review is given of the geodetic concepts necessary for oceanographers to make use of satellite gravity data to define the geoid, and to interpret the resulting product. The geoid is defined, with particular attention to subtleties related to the representation of the permanent tide, and the way in which the geoid is represented in ocean models. 5 The usual spherical harmonic description of th...

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 ...

The determination of the orthometric height from geometric leveling has practical difficulties that, despite a number of scientific and technological advances, passed a century without substantial modifications or advances. Currently, the Global Navigation Satellite System (GNSS) has been used with reasonable success for orthometric height determination. With a sufficient number of benchmarks w...

The impact of new geoid height models on estimates of the ocean circulation, now available from the Gravity Recovery and Climate Experiment (GRACE) spacecraft, is assessed, and the implications of far more accurate geoids, anticipated from the European Space Agency’s (ESA) Gravity and Ocean Circulation Explorer (GOCE) mission, are explored. The study is based on several circulation estimates ob...