Iterative current inversion method based on adaptive threshold selection technique
An adaptive threshold and technology technology, applied in the field of remote sensing technology, can solve problems such as poor versatility and poor adaptability
Active Publication Date: 2012-07-11
哈尔滨哈船导航技术有限公司
View PDF0 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
[0012] This method mainly has the following deficiencies: ①The surface laminar current measured by X-band radar should be the average flow information in the analyzed area, while the flow obtained by fitting the energy-weighted least squares method tends to flow with relatively large energy waves; ② The method of relying on experience to select the threshold value is not adaptable, and the empirical value of different sea areas and sea conditions is different, which needs to be obtained through a large number of experiments, and the versatility is not good
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0098] Combine below Figure 5 , 6 , 7, the present invention is described in more detail:
[0099] (5) Radar image collection and A\D conversion to get 32 original radar images.
[0100] The X-band navigation radar works under short pulses. Bragg scattering occurs between the emitted electromagnetic waves and the capillary waves on the sea surface, and the backscattering is received by the receiver. The video signal is converted into a digital signal by A / D, and the video signal between the two bow signals To form a radar image, in the present invention, 32 consecutive radar images g(x, y, t) need to be used, where x, y are respectively two components of the radar image space, and t is a time component.
[0101] (6) Obtain the image under Cartesian coordinates and perform Fourier transform to obtain the image spectrum.
[0102] Select the rectangular frame to be analyzed in the radar image, and use the nearest point interpolation to realize the transformation of the rada...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The present invention provides an iterative current inversion method based on an adaptive threshold selection technique, which comprises the following steps: (1) collecting radar images and carrying out A / D (analogue / digital) conversion to obtain 32 original radar images; (2) obtaining images within Cartesian coordinates and then obtaining an image spectrum through Fourier transformation; (3), determining initial estimates, only taking influence of 0-order secondary waves into consideration, and obtaining a rough flow through inversion; and (4) iterating fitting flow information by adopting a average weighted least squares method based on the adaptive threshold selection technique, taking influence of the 0-order secondary waves and 1-order secondary waves into consideration. By adopting the method, wave signals can be automatically identified, wave energy can be accurately separated from the image spectrum, the insufficient empirical value can be made up, the current trend can be better reflected, and the purposes of fewer errors and better stability can be achieved.
Description
technical field [0001] The invention relates to a remote sensing technology, in particular to an ocean remote sensing technology based on X-band navigation radar. Background technique [0002] Current meters (current meters, acoustic current profilers) can measure current information on the sea surface, but they are easily damaged by man-made or natural disasters, so they are currently only used in marine scientific investigations. Form a real-time and effective operational monitoring capability. [0003] X-band radar can not only monitor moving targets, but also measure ocean current and wave information when it works in short pulse mode. The measurement of current velocity (size, direction) is the key technology for X-band radar ocean wave monitoring. Compared with other marine sensors (wave buoys, current meters), the X-band radar has a wider detection range, high safety, and simple maintenance. It can be used as a substitute for wave buoys and current meters. Many unit...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01S7/41
Inventor 卢志忠戴运桃刘利强贾瑞才王淑娟李焱李英张立娜王凯胡浩
Owner 哈尔滨哈船导航技术有限公司