Topogeodetic operations are carried out with the view of horizontal-vertical positioning
for gravity observation stations. They are performed in the State system of elevation coordinates. The technical guides for operations are:
- instruction for topographic-geodetic and navigation provision of geological exploration, 1997;
- instruction for gravity exploration, 1980.
Elevations and coordinates are determined using sets of two-frequency GPS-instrumentation Trimble R7 in differential kinematic mode with post-processing. The base stations are located at the field base of the party and within the survey area.
The current processing of field materials is made every day at the field base. It includes:
1) Check of the quality of field measurements after the transfer of data from the field equipment to the computer.
2) Input of differential corrections.
3) Transmission of non adjusted coordinates and elevations from the base stations to the field observation ones.
Assessment of the quality of obtained vectors and the misclosure of closed polygons.
In-office processing of the materials is performed after the completion of field operations. It includes:
1) Tie of the base stations with the stations of the State geodetic network and with each other.
2) Tie of the field gravity observation grid with the base stations and the triangulation ones.
3) Assessment of the survey quality from the results of control measurements.
4) Compiling of the catalog of coordinates and elevations of observation stations.
Topogeodetic operations
Metrological provision of operations
Gravimetry instrumentation
Every year, before starting the surveys, the gravity meters
should be subject to a metrological calibration at the gravimetry
test site № 5 in Saint Petersburg.
The accuracy of field measurements is ensured by compliance
with the instructions and recommendations for execution
of field operations.
GPS-instrumentation for horizontal-vertical positioning
The GPS-receivers Trimble R7 to be used should be verified
at CJSC NPP «Navgeokom» (Moscow)
and accepted for the use as working measuring means.