Analysis of the accuracy of the sounder
Depth sounder accuracy should be understood as the accuracy of the corrected depth sounder. The depth sounder's depth accuracy depends primarily on the accuracy of the system error and possible random errors that affect the water depth value. The total propagation error consists of all the sounding errors caused by the factors affecting the sounding, including: 1 sound velocity error related to the acoustic signal propagation path (including the sound velocity profile), water temperature, salt content and static pressure for ultrasonic propagation The effect of speed is most pronounced by temperature. Generally, the water temperature decreases with the increase of water depth, and the water pressure increases with the increase of water depth. Therefore, the decrease of temperature and the increase of water pressure almost cancel each other on the speed of sound. The slope error of water bottom is also the signal reflected by sound waves when the bottom of the water is uneven. The time is inconsistent, resulting in a measurement error in the measurement depth caused by a fairly wide echo signal band on the display; 2 the system error of the sounding and positioning instrument itself; 3 tide measurement and model error; 4 ship heading and ship shake error ;5 positioning error due to incorrect installation of the transducer; 6 errors caused by the accuracy of the motion sensor of the vessel, such as the accuracy of the vertical and horizontal motion, dynamic draught error; 7 data processing error and so on. In short, the method to improve the sounding accuracy of the sounder is to use as many high-precision instruments as possible to monitor and attenuate various errors in the measurement. On the other hand, various error models are used for error estimation.
Depth sounder application
The depth sounder can be used to measure the depth of water. It is a marine navigation instrument that measures water depth. The ship can identify the ship position by measuring the water depth; when navigating the new navigation area or sailing in the shallow water area, the ship can be navigated to ensure the safety of the ship; in terms of channel and port measurement, it can provide accurate water depth data. Among the many navigation instruments, the echo sounder is still one of the essential navigation devices for ships.
The sounder can also be the main tool for measuring seabed topography. Seabed topography is a measure of the undulating shape and features of the seabed. It is an extension of terrestrial topography in the sea. According to the measurement area, it can be divided into three kinds of seabed topography: coastal zone, continental shelf and ocean. The feature is that the measurement content is high, the precision is high, and the display content is detailed.
The current urban river channel construction and remediation has become an important part of the construction of eco-city. Through the sounder, the basic mapping of urban rivers can be effectively carried out, the underwater depth can be obtained, the underwater landscape of urban rivers can be obtained, and the construction of ecological city can be realized. Planning provides a strong guarantee.