A transfer method of depth datum level in bathymetry

Abstract

The invention discloses a method for transmitting a depth reference plane for bathymetry, which belongs to the field of marine surveying and mapping. During the bathymetry period, wave effect correction and static draft correction are performed on the high ground water level data measured by a GNSS receiver on board a ship, and the drifting period and The dynamic draft is calculated and separated from the observation data during the sounding period, and the clean geodetic height reflecting the change of water level is calculated, and then the datum deviation between the reference ellipsoid and the local depth datum in the survey area is calculated by using the least squares fitting method, so that the The geodetic high water level measured by the ship's GNSS receiver is converted to the local depth datum in the survey area. Finally, the converted water level is used to control the water level of the bathymetry results to realize the conversion of the bathymetry results to the local depth datum. The method is simple in operation, reliable in quality, can accurately reflect the relative change of water level in the survey area, and has high conversion accuracy, so it has certain application value.

Description

technical field [0001] The invention belongs to the field of marine surveying and mapping, and in particular relates to a transfer method of a depth reference plane for bathymetry. Background technique [0002] In marine surveying and mapping, the commonly used vertical datums include local mean sea level, depth datum, elevation datum, etc. In hydrographic surveying, the depth datum is used as the starting plane for water depth, and in land surveying, the elevation datum is used as the starting plane for elevation. noodle. In order to meet the demand, my country has established a series of tide gauge stations along the coast from south to north, and calculated the depth datum in each region. However, because the vertical position of the depth datum is related to the local tidal range, the depth of my country's sea area The datum is not seamless and continuous, and the conversion relationship between the depth datum and the elevation datum in the coastal waters has not been f...

AI Technical Summary

Problems solved by technology

However, in small and medium-sized marine bathymetry or seabed topographic survey projects, it is often faced with the situation that some measurement areas are far away from the shore (15-40km), it is inconvenient to arrange tide stations on the side of the sea area, and there is no suitable datum deviation model. The working distance of the shore tide gauge station is limited, and the water level cannot be effectively controlled, resulting in the inability to perform datum conversion through the method of elevation or depth fitting

However, if the datum deviation is regarded as a constant, it will lead to a large conversion error

Therefore, in this case, it is impossible to accurately convert the bathymetry results of the survey area to the local depth datum, which brings difficulties to the bathymetry work

In response to this situation, the current common solution is to set up a self-contained tide gauge station on the seabed of the survey area, but this method has limitations such as high cost, unstable data, and easy loss

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