Large reservoir sounding reference field construction method and application

Abstract

The invention provides a large reservoir sounding reference field construction method and application. The method comprises the steps of reference field site selection: in order to meet the calibration technical requirements of various sounding devices, arranging reference points and reference surfaces in various forms, constructing a reference point, and constructing a reference plane. Research on sounding errors, positioning errors and water level correction errors can be carried out on the basis of the sounding reference point, including the nominal precision of a depth finder, the sounding mode, the actual sounding depth and the dynamic draft influence, positioning precision, GNSS data updating rate, difference method influence and the like, a water level calculation model and the like. Based on the depth sounding reference surface, depth sounding environment error research and GNSS three-dimensional water channel depth sounding precision research can be carried out. The influence research includesa wave effect, a positioning center deviation effect, a single-beam sounding attitude effect, a sounding delay effect, a ship speed effect, a beam angle effect, a coupling effect, water body characteristics, sounding sampling frequency and smoothing mode, sound ray tracking and multi-beam sounding system sounding point cloud precision analysis.

Description

technical field [0001] The invention belongs to the technical field of reservoir sounding, and in particular relates to a construction method and application of a large-scale reservoir sounding reference field. Background technique [0002] Problems facing the current sounding: [0003] (1) After the reservoir is impounded, the impact of the sounding environment on the sounding accuracy tends to be complicated. [0004] The average working water depth of inland water depth measurement in my country is generally less than 50m, and large water depth measurement is generally more common in ocean measurement. Due to the different operating environments (water depth, water temperature, flow field, wave, salinity), the accuracy requirements are different, and the observation methods and indicators followed are not suitable for inland water bodies. After the impoundment of important reservoirs in the Three Gorges and its upper reaches, the water depth doubles. For example, after ...

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Problems solved by technology

It will cause the change of sound velocity and cause the refraction of sound rays, which will seriously affect the sounding accuracy of canyon reservoirs

[0005] (2) After the reservoir is impounded, the sounding accuracy of the conventional depth sounder is limited under the condition of large water depth

[0006] With the completion and operation of the Three Gorges and important reservoirs in the upper reaches, the water depth has increased significantly compared with that before the impoundment. The speed of the ship is measured, and the speed of the topographic observation ship in the Three Gorges reservoir area has been reduced to 4kn (2m / s). At the same time, in order to ensure the stability of the results, a section needs to be continuously observed twice, and finally the data with better accuracy is obtained, which seriously limits the operation. efficiency

At the same time, due to a series of problems such as the inability to completely eliminate the influence of the surveying ship attitude, the difficulty in synchronizing the time of the sounding and positioning signals, and the difficulty in correcting the beam angle effect, etc., especially the inclination angle of the nearshore slope is mostly between 0° and 30°, and the inclination angle of some reservoir sections is still low. It exceeds 30°, and the slope of special parts even reaches 90°, and the beam angle effect is further amplified. Therefore, the current large water depth observation accuracy has been maintained within 1% of the relative water depth, and it is difficult to make a breakthrough

[0007] (3) There is a lack of benchmarks for high-precision sounding technology research under large water depth conditions

[0008] The biggest problem in the study of underwater terrain observation accuracy is that the underwater terrain is constantly changing under the action of water flow, and it cannot have a stable true value like the shore topographic observation, which can be used as a benchmark for bathymetry research

Therefore, the current "Water Channel Observation Standards" (SL257-2017) uses repeated observations to evaluate the accuracy of underwater bathymetry, and analyzes and counts the difference between repeated observations. Due to the lack of high-precision and stable underwater reference points (this bottom terrain), so it belongs to the concept of relative accuracy, it is difficult to observe and count the absolute accuracy, and further analyze the factors affecting the sounding accuracy, creating obstacles for targeted research

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