Accession Number : AD0634932

Title :   APPLICATION OF THE GRAVIMETER FOR MEASUREMENT OF GRAVITY AT SEA,

Corporate Author : AERONAUTICAL CHART AND INFORMATION CENTER ST LOUIS MO LINGUISTIC SECTION

Personal Author(s) : Shan-yen, Chang ; Hsi-chi,Li

Report Date : MAY 1966

Pagination or Media Count : 27

Abstract : The major problem encountered in the application of the gravimeter for measurement of gravity at sea is the continuous effect of ocean waves and the motion of the ship on the instrument. Specific examples of these disturbances are the inclination of the ship, periodic horizontal acceleration and vertical acceleration, et cetera. In studying the effects of horizontal acceleration on gravity meter readings, discussion centers on long-period and short-period stable platforms. It is known from the results of investigation, that when the period of the stable platform is long enough, it is possible to cancel out the effects of horizontal acceleration. In the case of a short-period stable platform, it is imperative to take into consideration second-order correction for the horizontal acceleration; moreover, the correction induced by damping and the finite period of the stable platform must be taken into account. Furthermore, the effects of vertical acceleration on gravity meter readings, and cross-coupling effect, can be eliminated during construction of the instrument and in the measurement-taking process. At the same time, this paper also studies acceleration correction for relative motion of the ship and the earth, and the necessary depth correction and bathymetric correction for calculation of gravity anomalies. (Author)

Descriptors :   (*MARINE GEOPHYSICS, *GRAVITY), OCEANOGRAPHIC EQUIPMENT

Subject Categories : Physical and Dynamic Oceanography
      Geodesy

Distribution Statement : APPROVED FOR PUBLIC RELEASE