IAG-IASPEI 2017

Presentation information

Oral

IAG Symposia » G02. Static gravity field

[G02-3] Regional gravity and geoid

Tue. Aug 1, 2017 8:30 AM - 10:00 AM Room 502 (Kobe International Conference Center 5F, Room 502)

Chairs: Hussein Abd-Elmotaal (Minia University) , Riccardo Barzaghi (Politecnico di Milano)

9:00 AM - 9:15 AM

[G02-3-03] Terrestrial gravity data for a new Russian quasigeoid model

Ilya Oshchepkov (Center of Geodesy, Cartography and SDI, Moscow, Russia)

A new quasigeoid model for Russia is planned to be calculated in the next few years.
For this purpose the gravity database was created from the geological gravity surveys which
were carried out from the late 1940s to the 2000s. This means there are on the average 0.1-0.25 points per squared kilometre with an accuracy of the Bouguer anomalies 0.8-1.0 mGal. Usually, but not always, each gravity point has geodetic coordinates, the normal height, the free-air anomaly, the Bouguer anomaly with a density of 2.3 g/cm^3, the refined Bouguer anomaly with a density of 2.67 g/cm^3 and the terrain correction. These values are strictly related to each other and can be easily checked for inconsistencies and errors, but unfortunately they don't cover the whole Russian territory, because not all the surveys were digitized yet.

In 1980th the mean Bouguer (with a density of 2.67 g/cm^3) and the Faye gravity anomalies with the resolution of 5'x7.5' were calculated directly from the gravity maps for the whole USSR territory and around its borders. These gridded data are almost complete for the whole area, but they have not been evaluated since the creation, which is done in this work by comparing them with the database points and the global gravity field models.

The new gridded Bouguer anomalies for Russia were created with GMT software by concatenating after gridding the point database with the old grid data to fill-in the gaps. The Faye anomalies were derived by subtracting the Bouguer plate reduction calculated with the RuDTM2014 digital elevation model.