APPLICATION OF TIME MEASUREMENTS FOR DETERMINATION OF GRAVITY POTENTIAL CHANGES

• Published in: International Multidisciplinary Scientific GeoConference : SGEM Vol. 17; pp. 115 - 122
• Main Authors: Rzepecka, Zofia, Kuczynska-Siehien, Joanna, Birylo, Monika
• Format: Conference Proceeding
• Language: English
• Published: Sofia Surveying Geology & Mining Ecology Management (SGEM) 01.01.2017
• Subjects: Accuracy; Clocks; Dynamic height; Earth; Earth gravitation; Frequency stability; Geodesy; Geodetics; Geopotential; Gravitation; Gravitational fields; Gravity; Gravity field; Groundwater; Magnetic fields; Measuring instruments; Relativism; Relativity; Stability; Theory of relativity
• ISSN: 1314-2704
• DOI: 10.5593/sgem2017/22

The chronometric geodesy is based on a relationship derived on the basis of the general theory of relativity, indicating a change of frequency and time at occurring change of potential. It is known that there is a possibility of using these relationships to determine geopotential changes, thus also height changes, by examining changes of clock rates in various places. From the formulas that describe this relationship, it can be estimated that at geopotential change by 1 m2/s2 (which corresponds to a height difference of about 10 cm in the average Earth gravity field) the relative clock frequency will be changed by 10-17. Thus clocks with the relative frequency stability of the order of 10-17 could be used for 10 cm height differences measurements; to detect a height difference of 5 mm, a clock of stability on the order of 5 · 10-19 should be used. Many authors are interested in this subject nowadays, it is a result of rapid technological progress and creation of increasingly accurate clocks. So far, the accuracy was improved by 1 order per each 10 years. The goal of this paper is to perform theoretical research to estimate required clock accuracy and compare it with currently available clocks. On the basis of our research it was proved that for admitted conditions, the limit clock stability should be between 10-18 and 2 · 10-20, to ensure sufficiently accurate measurements of gravitational potential variations.