5 results about "Echo sounding" patented technology

The application discloses a pressure type wave measuring instrument metering calibration device and method, relates to the technical field of hydrological measuring instrument calibration, and comprises the following steps: a wave simulation device drives a lifting platform to make periodic lifting movement according to a set wave height and a wave period, wave height measurement values of the pressure type wave measuring instrument and water depth measurement values of an echo sounder are collected; the water depth measurement values are converted into water depth standard values according to a correction value fitting function of the echo sounder; wave height standard values are calculated from the water depth standard values of each period, and an arithmetic average value is obtained as a standard wave height; the wave height measurement values are subjected to arithmetic averaging, and the difference between the arithmetic average value and the standard wave height is a wave height indication error. The lifting platform is driven to move again, a time interval corresponding to adjacent wave crests or troughs collected by the pressure type wave measuring instrument is taken as a wave period measurement value, a time interval corresponding to adjacent movement turning points of the lifting platform is taken as a wave period standard value, arithmetic average values are respectively obtained, and a difference value is taken as a wave period indication error.

This invention relates to a method for measuring the acoustic absorption coefficient of the shallow seabed, comprising the following steps: measuring the seawater depth of the experimental sea area using an echo sounder; measuring the average sound energy density generated by rainfall using a hydrophone vertical array; measuring the rainfall intensity using a rain gauge; measuring the sound power radiated underwater by rainfall per unit area of ​​the sea surface; and calculating the acoustic absorption coefficient of the shallow seabed. The measurement method of this invention has a clear principle, and by measuring the underwater noise generated by rainfall, it can cleverly measure the acoustic absorption coefficient of the shallow seabed across the entire frequency band.

This invention discloses a multi-echo detection method for a multi-beam echo sounding system with combined amplitude and phase features. The pre-detection step includes: segmenting the beam output signal; for each unit to be detected, obtaining an amplitude detection threshold using the unit average constant false alarm rate (CFAR) method based on background noise estimation from the reference units on the left and right sides; extracting the instantaneous phase from the signals of each receiving channel using Hilbert transform, and obtaining the phase coherence factor between each receiving channel from statistical characteristics; dynamically adjusting the amplitude detection threshold as an adaptive weight to construct a detection threshold for combined amplitude and phase features; initializing weighting coefficients based on echo intensity differences, and dynamically optimizing them in conjunction with the intensity value of the phase coherence factor to obtain an adaptive weighted amplitude and phase joint detection threshold; merging sampling points exceeding the adaptive weighted amplitude and phase joint detection threshold, removing interfering targets, and identifying and extracting multiple independent effective target intervals.

The application discloses a kind of thin-wall steel cofferdam construction measurement control methods on underwater inclined bank slope, and the application is guided steel cofferdam section processing, in-situ assembly, overall lowering, etc., by steel cofferdam construction measurement control method.This application includes steel cofferdam processing acceptance based on line orientation method, in-situ assembly measurement based on ranging method, riverbed scanning based on echo sounding principle, magnetic adsorption prism is used to lay deformation monitoring point, and the three-dimensional posture and deformation of steel cofferdam during lowering process are observed, which guides steel cofferdam heightening and sinking construction, and ensures the smooth construction of thin-wall steel cofferdam on inclined bank slope.The application has the advantages of completing steel cofferdam processing and manufacturing, on-site assembly, full-process observation during lowering and heightening, ensuring smooth steel cofferdam construction, structural safety and accurate position, effectively solving the problem that the perpendicularity of steel cofferdam cannot be directly observed in the method of platform first and steel cofferdam construction.

A polar vessel is disclosed. The polar vessel includes: a keel protruding from the lower part of the vessel; and an echo sounder mounted on the keel, configured to transmit ultrasonic pulses toward the seabed, receive ultrasonic pulses reflected back from the seabed, and calculate the depth of the seabed based on the time required for the ultrasonic pulses to return.