Some Recent Developments in Gravity Measurements Aboard Surface Ships

  1. Hyman Orlin
  1. Manik Talwani

Published Online: 18 MAR 2013

DOI: 10.1029/GM009p0031

Gravity Anomalies: Unsurveyed Areas

Gravity Anomalies: Unsurveyed Areas

How to Cite

Talwani, M. (1966) Some Recent Developments in Gravity Measurements Aboard Surface Ships, in Gravity Anomalies: Unsurveyed Areas (ed H. Orlin), American Geophysical Union, Washington, D.C.. doi: 10.1029/GM009p0031

Author Information

  1. Lamont Geological Observatory, Columbia University, Palisades, New York

Publication History

  1. Published Online: 18 MAR 2013
  2. Published Print: 1 JAN 1966

ISBN Information

Print ISBN: 9780875900094

Online ISBN: 9781118664018

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Keywords:

  • Aboard surface ships;
  • Analog cross–coupling computer;
  • Errors of gravity measurement;
  • Graf–Askania Sea gravimeter;
  • Gravity measurements;
  • Histogram of cross–coupling error

Summary

Errors experienced by surface ship gravimeters which arise from the ship's horizontal accelerations are discussed. Results from a continuously recording analog computer show that the cross-coupling errors can be appreciable under normal sea conditions. Off-leveling errors for the Anschutz gyrotable aboard R. V. Robert D. Conrad are small. It is shown that the off-leveling error in the determination of the Browne correction for a gimbal-suspended gravimeter is identical to the off-leveling error experienced by a gravity meter on a stable platform, provided that the same vertical reference is used and the servo errors are the same. The gyros are more error free as vertical references than are long-period pendulums. A simple slope correction can be applied to the record of the Graf-Askania Gss2 gravity meter to correct for the instrument response; thus "instantaneous" gravity values can be obtained. An analog computer to compute and record the Eotvos correction continuously has been developed. Data reduction and display procedures are described.