Temperature and Humidity Impact on the Accuracy of Chekan-AM Gravimeter

Abstract

Marine gravimetry aims to obtain accurate and reliable data on gravity field anomalies in water areas. Modern gravimetric systems such as Chekan-AM feature high accuracy due to the novel circuit and design solutions in the conditions specified in the technical description. The article discusses the influence of ambient temperature and humidity on the accuracy of the Chekan-AM gravimeter. These meteorological factors matter both during short measurement periods, within individual survey lines, and long periods, during expeditions far away from the reference points. For 18 months, the authors of the article have been carrying out laboratory tests of the gravimeter with simultaneous registration of meteorological parameters. Based on the observation results, the correlation dependences of the zero-point drift of the gravimeter sensitive element on seasonal temperature and humidity variations were calculated. Marine expeditions data were also studied, with analysis of the temperature impact over a short time period during the marine gravimetric survey. Based on the results of the experiments it was shown that meteorological monitoring should be performed in the course of gravimetric surveys, including those onboard research vessels. An additional thermal noise becomes noticeable in the survey conducted in an area with low variations in the gravity field, and it should be considered when analyzing and evaluating the results.