Underwater moving object location and navigation method and device based on frequency spectrum transformation

Abstract

The invention relates to an underwater moving object location and navigation method based on frequency spectrum transformation. In the method, (1) an onboard underwater sound transceiver transmits a symmetric triangle frequency modulation signal s(t) to an underwater moving object; (2) an underwater receiver array on an onboard measurement device receives echo signals; (3) the weight number of each array element in the underwater sound receiver array is adjusted by utilizing information of signals in the direction of an incoming wave; and (4) the onboard measurement device determines the coordinates of the underwater moving object in geodetic coordinates. An underwater moving object location and navigation device based on spectrum transformation mainly comprises the onboard measurement device, a shiphull posture correction device, an underwater sound transceiver on the underwater moving object, a water radio transceiver, an array signal processor, a GPS receiver and a microprocessor. The invention can not only track and locate the underwater object above water, seas on shore or in air, but also automatically locate and navigate underwater objects.

Description

technical field [0001] The invention relates to a method and device for positioning and navigating an underwater moving target based on frequency spectrum transformation. Background technique [0002] Sea surface and underwater positioning and navigation are the basic prerequisites for all ocean development activities and marine high-tech development. Underwater motion carriers or equipment platforms are important tools for ocean development. In practical applications, in order to determine their underwater positions, positioning is often required. . Due to the severe attenuation of electromagnetic waves in water, the GPS system on land is not suitable for the positioning of underwater targets. Sound waves have good propagation characteristics in water. The current underwater positioning generally uses sound waves as the medium, mainly including long baseline positioning systems, short baseline positioning systems and ultra-short baseline positioning systems. Assuming that...

AI Technical Summary

Problems solved by technology

The underwater acoustic channel is an extremely complex time-variant-frequency-space-variant random narrowband channel, which has the characteristics of high attenuation, strong multipath interference, serious Doppler frequency deviation, and narrow available frequency band. These characteristics are especially strong multipath interference. It causes certain interference to the reception and detection of the underwater acoustic signal of the single-frequency pulse signal, which seriously affects the accuracy of the underwater acoustic positioning system

However, the distance between the array elements that make up the long baseline positioning system is required to be greater than 100m, and they are deployed at different positions on the seabed, requiring cumbersome calibration work, which limits the application of positioning methods based on echo round-trip time delay

[0004] The distance between the array elements of the ultra-short baseline positioning system is required to be less than half a wavelength, which has the advantage of small size, but the system estimates the angle of incidence by measuring the phase difference between the array elements, and then uses the intersection of straight lines for positioning, which has the disadvantage of low accuracy. defect

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