Abstract: An identification method of seabed weak echoes in airborne LiDAR bathymetry and a system thereof are provided, which belong to the technical field of marine surveying and mapping. The method includes: dividing sea area laser pulses into surface-seabed pulses or seabed-undefined pulses based on preprocessed data; using two-stage local maximum method to determine potential seabed echo positions of ALB waveforms and pre-generate seabed points; defining an ellipsoid neighborhood related to density and extracting spatial features of a pre-generated point cloud; constructing a BP neural network to identify seabed points in the pre-generated point cloud, and optimizing the identification result of the seabed points based on a laser pulse echo sequence and point cloud density.
Abstract: The present disclosure relates to a calculation method, a storage medium and a device for a seabed reflection coefficient of point source elastic wave. The method includes initializing a calculation accuracy and a calculation range of the seabed reflection coefficient; discretizing a parameter space and obtaining the seabed reflection coefficient of point source elastic wave; combining an equivalent equation and a traditional calculation equation for the seabed reflection coefficient of point source elastic wave; solving an undetermined coefficient of the equivalent equation; obtaining a concise expression for the seabed reflection coefficient of point source under an accuracy in the first step; calculating the seabed reflection coefficient of point source elastic wave within a given calculation accuracy range using an obtained expression.
Abstract: The present application provides a seafloor multi-wave seismic source including: a pressure chamber mechanism; a high-voltage pulse generator with four discharge pathways; a thrust mechanism with a thrust rod and a thrust head; four vibrators are evenly distributed around a periphery of the thrust head, and each vibrator is connected with one discharge pathway of the high-voltage pulse generator; a power supply unit to power the seismic source; and a processor, a memory and a program, wherein the program is stored in the memory and configured to be executed by the processor; and the program includes: pulse emission instructions generated by the processor based on user settings and received by the high-voltage pulse generator, for switching on four or any two of the four discharge pathways at the same time, to enable the corresponding vibrators to vibrate to excite seismic waves in compression wave mode or shear wave mode.
Type:
Grant
Filed:
February 28, 2022
Date of Patent:
September 5, 2023
Assignee:
FIRST INSTITUTE OF OCEANOGRAPHY, MNR
Inventors:
Yanliang Pei, Kai Liu, Mingming Wen, Chenguang Liu, Yifan Huang, Liancheng Zhang, Keping Yan, Baohua Liu
Abstract: The present disclosure provides a LADCP-USBL combined observation and data processing method and an apparatus. According to one embodiment, an exemplary method may include: acquiring bottom tracking data from the LADCP, position trajectory data collected by the USBL, and ocean current data collected by the LADCP; removing abnormal data points from the position trajectory data; performing azimuth angle correction on the position trajectory data according to the bottom tracking data to determine a movement velocity of the LADCP; and calculating an absolute ocean current velocity according to the movement velocity of the LADCP and the ocean current data.