Method for calculating gravitational potential difference between sea-crossing elevation points

Abstract

The invention discloses a method for calculating gravitational potential difference between sea-crossing elevation points, which is used for determining the elevation of islands (reefs) around the land in coastal countries. The method comprises the steps of carrying out astronomical geodetic plumb deviation, gravity and GNSS geodetic height measurement on elevation points on two sides of land and an island; measuring measuring point gravity data and GNSS sea surface height between land and sea in a shipborne gravity / GNSS measuring line mode, and reducing corrected gravity / geodetic height data to an average sea surface; deducing a calculation formula of a gravity potential difference between sea-crossing elevation points according to a gravity potential theory and an astronomical level principle; in combination with astronomical earth vertical line deviations on elevation points on the two sides of land and sea, improving the vertical line deviation precision of measuring lines and measuring points according to a removal-recovery technology; and substituting the result into a deduced gravitational potential difference calculation formula to realize sea-crossing gravitational potential difference calculation. The gravitational potential difference between sea-crossing elevation points is calculated by utilizing actually measured elevation point data of a certain place in Shandong Province, the distance of the elevation points is about 10.5 km, and an elevation value calculated according to the gravitational potential difference meets the level measurement accuracy requirement of the national level measurement specification III.

Description

Technical field [0001] The present invention relates to a method of calculating a gravity zone difference between a long-distance cross-sea elevated point, in particular, a linear cross-sea elevation of astronomical landlines, GNSS measurement, and carrier gravity / GNSS. Calculation method of gravity selections between disc. Background technique [0002] The gravity fraction calculation of the cross-sea elevated point can be used to complete the land, the island elevation benchmark. my country is a marine big country, with many islands (reefs) in coastal areas. Establishing a unified island (reef) elevation system, which can serve the development and protection of islands (reefs), marine environmental protection, marine disaster monitoring and marine resource exploration and development. Therefore, the unified land sea elevation system is of great significance in scientific research, national economic construction and national defense construction. Traditional gravity zerogenic ...

AI Technical Summary

Problems solved by technology

This method applies the theory of gravity potential difference to the cross-sea elevation transfer. In this method, the sea surface dynamic topography difference is one of the main factors affecting the calculation of the potential difference. Since the sea surface dynamic topography cannot be measured on site, only The difference between the average sea surface obtained by satellite altimetry and the geoid obtained by the earth's gravity field model is obtained to obtain the dynamic sea surface topography. Due to the resolution problem of the altimetry sea surface height model and the earth's gravity field model, there are many gaps between the measured results and the reduced The accuracy of the calculation results of gravity displacement is improved

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