First Institute of Oceanography, Ministry of Natural Resources

First Institute of Oceanography, Mnr

Yanxiong Liu

Fangli Qiao

Yang Liu

Jie Li

Jingsong Guo

Li Tian

Yanfeng Wang

Guanxu Chen

Menghao Li

Chen Xue

Shumin Jiang

Wenxue Xu

Deming Ma

Yadong Guo

Qiuhua Tang

Yikai Feng

A wave spectrum calculation method based on GNSS wave measuring buoy is provided, which includes: placing GNSS drift buoys in the sea, collecting buoy position data; then obtaining three-dimensional velocity data of ocean waves; performing high pass filtering on velocity data of a sliding window to remove noise signals and trend terms, retaining wave motion data; calculating a cross spectrum and wave direction spectrum. The present disclosure solves limitations of traditional GNSS measurement methods applied to ocean buoy wave measurement, such as limited observation distance, high cost, tedious measurement and average calculation accuracy, and a need for correction services. The measurement accuracy is high and no additional correction services are required, which is more suitable for wave measurement, the wave spectrum algorithm in this method can adapt to more complex observation environments and incorporate results of a velocity measurement algorithm into a matched wave spectrum algorithm.

Wave spectrum calculation method based on GNSS wave measuring buoy

The disclosure provides a broadcast-type underwater navigation positioning system and method, wherein the system comprises a base station network consisting of a plurality of underwater base stations distributed on a seabed and a to-be-positioned user terminal located underwater, wherein the underwater base station comprises a bottom-mounted sonar and an mooring sonar, the bottom-mounted sonar and the mooring sonar are connected through a cable and are configured for ranging and communication through an underwater acoustic signal, the mooring sonar is integrated with an inertial measurement unit I, and the user terminal is provided with a passive sonar configured to unidirectionally receive an underwater acoustic signal sent by the mooring sonar for ranging and communication. The underwater navigation positioning system and method disclosed in the present invention can expand the service range of the base station, increase the capacity of the user terminal and improve the precision of regional sound velocity products.

Broadcast-type underwater navigation positioning system and method

A new GNSS-based real-time high-precision wave measurement method, wherein the GNSS phase, pseudo-range, Doppler frequency shift observations and broadcast ephemerides are collected by a GNSS receiver, and antenna carried by a sea surface carrier; the three-dimensional speeds of a carrier are acquired using an epoch difference of phase observations; and wave element information are then solved. The wave element information can also be obtained by integrating the speeds for a certain duration and removing a linear trend term to obtain a time-dependent displacement variations. No additional precise differential correction is needed, thereby saving on service costs and communication costs of precise differential corrections. High-precision wave element information is obtained in real time, and locally stored in a buoy or periodically returned by communication, thereby expanding the working range of GNSS-based ocean wave measurement.

GNSS-based real-time high-precision wave measurement method and apparatus

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.

Identification method of seabed weak echoes by airborne LiDAR bathymetry and system thereof

Growing community of inventors

Qingdao, China

Yanxiong Liu