Full Title Aero-Gravimeter Tech Area / Field

• OBS-NAT: Other Basic Sciences / Natural Resources and Earth Sciences
• INS-MEA: Instrumentation / Measuring Instruments

Brief Description of Technology
Detailed information on the Earth’s gravity field is necessary for many branches of applied science (geology, navigation, earth-shape science etc.). A gravimeter is a fine instrument intended for the measuring of gravity (g). The accuracy of the best land-surface gravimeters is about 10^-8 g. The best results of measurements on board of moving vehicles do not exceed 10^-7 g for sea gravimeters and 10^-6 g for air gravimeters.

So far, two problems prevent scientists from achieving an accuracy in on-board gravimeters close to the accuracy in on-land stationary gravimeters. The first problem is the problem of gravity-sensor and gyro-stabilizer design, concerning the moving vehicle inertial acceleration which changes in range are more than million times greater than the permissible measuring error. The second problem is caused by the difficulty to separate the gravity from the inertial acceleration in gravity sensor output data. The CSRI "Elektropribor" has a positive experience in solving this problem for sea gravimeters, and is now trying to develop an air-sea gravimeter. To achieve this aim it is necessary:
- to design a more compact and more precise gyro-stabilizer unaffected by airplane maneuvers;
- to modernize double quartz gravity-sensors by replacing the optic-electronic-mechanical transducer by an optic-electronic transducer, using a charge-coupled-device;
- to develop a highly precise system of vertical airplane motion measuring based on differential satellite navigation and an altimeter which has to provide a permissible error of about 1 sm;
- to develop special software for gravimeter output data processing and the correction of calculation, based on navigation instrument data.

To confirm the uniqueness and novelty of the above mentioned research, it is interesting to note that, despite of their advantages, aerogravimeters are only used in the United States. Other industrialized countries have not yet completed the necessary research in this area.

Legal Aspects
Three generations of marine gravimetric systems have been designed in CSRI "Elektropribor" over the last 25 years. For more than 10 years they have been the basic means of sea gravity survey in Russia. More than ten patent applications for the system, its parts and the measuring methods have been approved in Russia.

Special Facilities in Use and Their Specifications
Aerogravimetry allows to detect gravity anomalies up to 10^-6 g in amplitude and 3 - 5 km in length in any region of the world. It is irreplaceable in deserts, swamps, tropical rain forests and mountains.

Aerogravity surveys are very important in the search for gas and oil, taking into account that 70% of the earth’s perspective gas and oil supplies have not yet been discovered, and that most of them are difficult to access.

Scientific Papers
L.P.Nesenjuk, V.G.Peshekhonov, L.S.Elinson. Marine Gravity Systems. First Annual Workshop. “Russian Airborne Geophysics and Remote Sensing”, 13-17 September 1992, Colorado School of Mines, Golden, Colorado, USA, SPIE, V2111, 93.

Дата добавления: 2015-07-20