CN111045005B - Sea wave height calculation method, terminal and measurement system - Google Patents
Sea wave height calculation method, terminal and measurement system Download PDFInfo
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Abstract
The invention discloses a wave height calculation method of sea waves, which comprises the following steps: adjusting the pulse width of the radar to be minimum, collecting a first image sequence, and recording a first true course angle sequence and a first longitude and latitude coordinate information sequence of the ship; selecting an image inversion area, and performing inversion area motion compensation; inverting the sea wave information to obtain the dominant wave wavelength of the sea wave; adjusting the pulse width of the radar to enable the resolution of the radar to be equal to the main wave wavelength of sea waves, collecting a second image sequence, and recording a second true course angle sequence and a second longitude and latitude coordinate information sequence of the ship; selecting an image inversion area, and performing inversion area motion compensation; calculating the sea surface average radar cross section of the inversion area; and calculating the effective wave height of the sea waves. The method has the beneficial effect that the effective wave height can be inverted in all sea areas only by once calibration.
Description
Technical Field
The invention belongs to the technical field of ocean wave remote sensing, and particularly relates to a computing method, a terminal and a measuring system for an ocean wave height computing method.
Background
The microwave radar remote sensing test method is a novel wave remote measuring method emerging in the world for more than 20 years. The ship has the advantages of low cost, all-weather, small platform volume, capability of sailing with the ship and the like.
The technical scheme for telemetering sea waves by using a microwave radar is briefly described as follows: the microwave radar acquires a group of radar image sequences according to a time sequence, three-dimensional Fourier transform is carried out to obtain an image spectrum, then the image spectrum is converted into an ocean wave number spectrum through a modulation transfer function, and then the data of the flow velocity, the wave direction and the wave length of ocean waves are estimated. For the estimation of the effective wave height of the sea wave, a common method in the field of ocean remote sensing is applied to a Chinese patent 'a method for inverting the sea wave parameters by an X-band navigation radar based on a novel sea wave dispersion relation band-pass filter' (publication number: CN103969643B) and a Chinese patent 'dual-polarization X-band radar sea wave parameter measurement system' (publication number: CN 200910017953.8). The method is firstly proposed by Ziemer et al in 1994, and successfully applies the method for inverting the SAR image to the effective wave height of the sea wave to the marine radar, wherein the calculation formula is as follows:
wherein HsFor the effective wave height, the SNR is the image signal-to-noise ratio. A and B are undetermined coefficients and are key parameters for obtaining the effective wave height of the sea waves. The two parameters a and B were obtained in long-term calibration experiments under various sea conditions. The effective wave height obtained by inversion of the method is related to factors such as seabed structure and the like, and the parameters for one-time calibration are only suitable for a fixed sea surface. Therefore, the method is suitable for fixed land-based measuring equipment, but in a ship-borne application scene, when a ship sails to an unknown sea area, the effective wave height cannot be correctly inverted without calibration data corresponding to the sea area. Therefore, there is a need in the art for a method that can invert the effective wave height in all the sea areas with only one calibration.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a wave height calculation method for sea waves, and partial embodiments of the invention can be based on the effective wave height of the sea waves and the average radar cross section area sigma of the sea waves in the field of microwave radars0By measuring the relationship betweenMeasuring sigma of sea surface0The wave height of the sea wave is calculated. The relation is obtained from experimental data of sea clutter, and a large number of measurement verifications have been carried out in the 70 th century, which is a basic conclusion recognized in the radar field. Meanwhile, the invention applies the relation between the pulse width and the resolution in the pulse radar theory. The pulse radar carries out high-resolution imaging on the sea waves under narrow pulses, so that the flow velocity, wave direction and wavelength of the sea waves are obtained through inversion. Then according to the measured wave wavelength data, the pulse width of the radar system is adjusted, and the average radar cross section area sigma of the sea surface is measured through the collected echo data instead of the image0And obtaining the sea surface effective wave height data by inversion.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method of wave height calculation of ocean waves, the method comprising: adjusting the pulse width of the radar to be minimum, collecting a first image sequence, and recording a first true course angle sequence and a first longitude and latitude coordinate information sequence of the ship; selecting an image inversion area, and performing inversion area motion compensation; inverting the sea wave information to obtain the dominant wave wavelength of the sea wave; adjusting the pulse width of the radar to enable the resolution of the radar to be equal to the main wave wavelength of sea waves, collecting a second image sequence, and recording a second true course angle sequence and a second longitude and latitude coordinate information sequence of the ship; selecting an image inversion area, and performing inversion area motion compensation; calculating the sea surface average radar cross section of the inversion area; and calculating the effective wave height of the sea waves.
Preferably, the selecting an image inversion region comprises: and rotating the image counterclockwise by a true heading angle by taking the center of the image as an origin to enable the position right above the origin to be in a due north direction.
Preferably, the inversion region motion compensation comprises: and determining an image inversion area in the other image according to the selected image inversion area in one image according to the latitude and longitude coordinate difference between the centers of the two images.
Preferably, the wave information inversion comprises: according to the first image sequence, three-dimensional discrete Fourier transform is applied to obtain a three-dimensional wave number frequency spectrum; based on the gravity wave dispersion equation influenced by Doppler and the basic dispersion relation, the least square method is applied to calculate the flow velocity and the flow direction in an iterative manner; performing band-pass filtering on the three-dimensional wave number frequency spectrum; integrating the three-dimensional wave number frequency spectrum subjected to band-pass filtering according to the calculated flow velocity and flow direction and a dispersion equation influenced by Doppler to obtain a radar two-dimensional wave number spectrum; converting the radar two-dimensional wave number spectrum into a two-dimensional sea wave spectrum by using a modulation transfer function; and calculating to obtain the dominant wave wavelength of the sea wave according to the two-dimensional sea wave spectrum.
Preferably, the calculating the sea surface average radar cross-sectional area of the inversion region comprises: calculating the area of an inversion region; calculating the radar cross section of the inversion area; and calculating the sea surface average radar cross section of the inversion area.
A terminal is provided, wherein a computer program is stored in the terminal, the terminal receives an image sequence, a true course angle sequence and a longitude and latitude coordinate information sequence which are input from the outside, and loads the computer program to execute any one of the sea wave height calculation methods.
A wave height measurement system for a sea, the measurement system comprising: a radar capable of adjusting a pulse width; the signal acquisition unit is connected with the radar and is used for acquiring an image sequence; the navigation unit can acquire a true course angle sequence and a longitude and latitude coordinate information sequence of the ship; the digital signal processing unit is connected with the signal acquisition unit and the navigation unit and is used for calculating the effective wave height of the sea wave according to the image sequence, the true course angle sequence and the longitude and latitude coordinate information sequence; and
and the display unit is connected with the digital signal processing unit and is used for displaying the effective wave height of the sea waves.
Preferably, the navigation unit includes: the GPS module and the magnetic compass module are connected with the digital signal processing unit.
Compared with the prior art, the invention has the beneficial effects that: the method is based on the electromagnetic scattering property of the sea surface to invert the effective wave height of the sea wave, so that the measurement and inversion are only related to the surface sea wave and are not related to other factors such as a seabed structure, the biggest advantage of the method is that the effective wave height of all sea areas can be inverted only by once calibration, and the technical problem that the traditional method cannot invert unknown sea areas is solved
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In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a system configuration diagram of a wave height measuring system in an embodiment of the present invention.
Fig. 2 is a flowchart of an embodiment of a method for calculating a wave height of a wave in the embodiment of the present invention.
Fig. 3 is a flow chart of the calculation method for calculating the wave height of the sea wave for adjusting the radar resolution and the effective wave height of the sea wave in the embodiment of the invention.
FIG. 4 is a diagram of radar imaging geometry in an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without inventive effort based on the embodiments of the present invention, are within the scope of the present invention.
In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.
This example will describe an implementation of the present algorithm in an application scenario where civil ships are ocean-going. The system structure is shown in fig. 1, which is described in detail as follows:
in fig. 1, the marine X-band navigation radar is arranged 5 meters above the deck in the center of the ship. The radar adopts a pulse system, and the number of rotation turns is not less than 24 revolutions per minute. In order for a radar to be suitable for use in the present system, some adaptation is required: the heading, angle, triggering and video signals of the radar are led out and connected to a signal acquisition unit, and the radar pulse width control signals are led out and connected to a digital signal processing unit. The pulse width generating module is modified, so that the pulse width set by the radar can be used, and the pulse width of the radar can be changed in a program-controlled manner when needed. The modified pulse width control unit is connected with the digital signal processing unit.
The radar can be shared with the original navigation radar for the ship, and can also be independent of the original navigation radar for the ship.
In fig. 1, a signal acquisition unit is connected to a marine X-band navigation radar and acquires video signals under the control of three signals, namely heading, angle and trigger. The sampling rate is not lower than 20MHz, and the quantization digit is not lower than 8 digits.
In fig. 1, the high-precision GPS unit and the magnetic compass unit are respectively responsible for recording the position and the true heading angle of the ship in each picture. This is used in this embodiment, and other methods such as inertial navigation and the like can be used to measure the position and true heading angle of the ship.
In fig. 1, the digital signal processing unit processes the data collected by the signal collecting unit, and in this embodiment, a utilization control computer is used for processing. The digital signal processing unit receives the acquired radar echo signals and simultaneously receives the position information from the high-precision GPS unit and the magnetic compass unit. And after the acquisition is finished, completing the inversion of the wave parameters in the specified inversion area. In order to realize the measurement of the sea surface average RCS, the digital signal processing unit can control the pulse width transmitted by the marine X-band navigation radar. And sending the wave parameter data obtained after the inversion is finished to a display unit for displaying.
In this embodiment, the display unit uses a color liquid crystal display.
The algorithm in the digital signal processing unit is explained below. As shown in fig. 2-4, the method is implemented by the following steps:
step 1: and (5) radar image acquisition.
The radar used by the system can adopt a shipborne microwave pulse radar, the system adjusts the pulse width of the radar to be minimum, and a first image is acquired. And at the same time, recording the true ship heading phi corresponding to the image through equipment such as a compass and a GPS1With latitude and longitude coordinate information (LO)1,LA1). And after finishing, continuously acquiring the next image, wherein the time interval between two adjacent images is constant as t. And continuously acquiring N images, wherein the specific number is based on meeting the inversion requirement.
Step 2: and selecting an image inversion area.
Selecting a first image, and rotating the image counterclockwise by phi with the center of the image as an origin1The angle is the true north direction above the origin. And establishing a Cartesian coordinate system by taking the north as the positive Y-axis direction and the east as the positive X-axis direction. Selecting a reverse region (X) on the image1,Y1)、(X2,Y2)、(X3,Y3) And (X)4,Y4) The rectangular area in between is the inversion area.
And step 3: and performing inversion region motion compensation.
For the kth radar image (k is more than or equal to 0 and less than or equal to N), the image center is taken as the origin, and the image is rotated counterclockwise by phikAnd (3) establishing a Cartesian coordinate system according to the method in the step (2) after the angle is formed. By latitude and longitude coordinates (LO) of the kth imagek,LAk) Latitude and longitude coordinates (LO) from the first image1,LA1) Difference value, calculating the variation quantity DeltaX of the coordinates of the inversion region on the radar imagekAnd Delta Yk. And sequentially calculating inversion areas of the k image according to the following formula.
And 4, step 4: and (4) carrying out inversion on wave information.
And obtaining a wave spectrum of the selected area by using the compensated image sequence, and obtaining wave parameters including a main wave peak period, a main wave peak wave direction and a main wave peak wavelength by using wave spectrum inversion calculation.
The step (4) comprises
Step 4.1: and (5) calculating the spectrum of the radar three-dimensional wave number frequency image.
Selecting a continuous 32-image radar sequence and applying three-dimensional discrete Fourier transform to obtain three-dimensional wave number frequency image spectrum, i.e.
P(kx,ky,ω)＝|FFT(I(x,y,t))|2 (1)。
In the formula (1), P is a three-dimensional wave number frequency spectrum, I is a radar image sequence, x and y are two-dimensional coordinate systems, and t is a time sequence. k is a radical ofxAnd kyIs two vectors in the x and y directions of wave number, and ω is angular frequency.
Step 4.2: and calculating the flow speed and the flow direction.
Based on the gravity wave dispersion equation influenced by Doppler and the basic dispersion relation, the flow velocity and the flow direction are iteratively calculated by applying a least square method, and the calculation formula of the flow velocity and the flow direction is as follows:
in the formula (2), uxAnd uyAre the x and y directional components of the flow velocity. g is gravitational acceleration, ω is angular frequency, k is wave number, kxAnd kyThe components in the x and y directions of the wavenumber and d the depth of the water. And P is a three-dimensional wave number frequency spectrum.
Step 4.3: and (4) band-pass filtering.
In order to filter noise energy and obtain energy belonging to the sea wave spectrum, band-pass filtering is carried out on the three-dimensional wave number frequency spectrum through the following formula;
wherein,
where Δ ω is the frequency resolution and Δ k is the wave number resolution. U shapemaxIs the maximum desired flow rate.
Step 4.4: and (4) calculating a radar two-dimensional wave number spectrum.
And integrating the filtered three-dimensional wave number frequency spectrum according to the calculated flow velocity and flow direction and a dispersion equation influenced by Doppler to obtain a radar two-dimensional wave number spectrum:
in the formula (3), Ψ (k)x,ky) Is a two-dimensional radar wave number spectrum, E is a three-dimensional radar wave number frequency spectrum subjected to band-pass filtering, g is gravity acceleration, omega is angular frequency, k is wave number, k isxAnd kyThe components in the x and y directions of the wave number, d is the depth of the water,
is the surface flow velocity vector.
Step 4.5: and (5) calculating a two-dimensional wave spectrum.
The conversion from a two-dimensional radar wave number spectrum to a two-dimensional ocean wave spectrum requires the use of a modulation transfer function. Here a transfer modulation function is used having the form of an exponential power:
|M(kx,ky)|2∝kβ，
where β is an empirical coefficient, the empirical value obtained through a number of experiments is 1.2, taken here as 1.2. And (3) converting the radar wave number spectrum into a sea wave spectrum by using the transfer function:
I(kx,ky)＝|M(kx,ky)|2.Ψ(kx,ky)。
step 4.6: and (5) calculating a one-dimensional wave spectrum.
For research convenience, the wave spectrum in the cartesian coordinate system is converted into I (k, θ) in a polar coordinate system. Wherein:
the wave spectrum I (k, θ) expressed in polar coordinates is then converted into a direction spectrum F (F, θ):
f (F, theta) is integrated with respect to theta to obtain a one-dimensional frequency spectrum s (F).
Step 4.7: the main wave direction, wavelength and period are inverted.
In the two-dimensional sea wave spectrum obtained by inversion, the coordinates of the spectrum peaks are assumed as follows:
(kx,ky)，
the corresponding main wave direction β and main wave length l are:
the average period is:
wherein, the integration range is the upper and lower limits of the frequency spectrum.
And 5: sea surface average radar cross-sectional area σ0Measurement and calculation of effective wave height.
Adjusting the pulse width of the radar to make the resolution equal to the dominant wave wavelength by adjusting the measured dominant wave wavelength of the sea wave, acquiring data once again, and calculating the average radar sectional area sigma of the sea wave according to the echo amplitude of the corresponding area0。
The step (5) comprises
Step 5.1: and calculating the pulse width of the radar.
The radar used in the microwave radar wave remote sensing system is a pulse radar, the distance resolution of which is related to the pulse width and can be characterized by the following formula:
where c is the speed of light, τ is the pulse width, and Δ R is the range resolution. In order to accurately obtain the average RCS of the sea surface, the resolution of the radar needs to be adjusted to be consistent with the dominant wave length of the sea waves, and in this case, the echo amplitude is the same as σ0Is in direct proportion.
In step (4.7), the inversion results in that the dominant wavelength is l, and therefore, the pulse width τ of the radar should be adjusted to:
step 5.2: radar resolution adjustment and sea surface average radar cross section area sigma0And (6) measuring.
Firstly, the resolution of the radar is adjusted to be the same as the dominant wave wavelength of the sea wave, and the emission pulse width of the radar system needs to be adjusted to the pulse width tau calculated in the step (5.1).
And after the radar resolution is adjusted, acquiring the original data of the radar echo according to the same setting as the step 1 and imaging. And recording the true course and longitude and latitude coordinate information of the ship corresponding to the image through equipment such as a compass, a GPS and the like at the same time.
And (3) for the image with the radar resolution changed, performing motion compensation on the inversion area according to the method in the step 3.
The area of the inversion region is first calculated. Considering an imaging model of the radar, if the height of the radar from the sea surface is h, the imaging length of a target on the radar is delta b, and the target is delta a and r away from the radar upwards at a certain distance.
At the target, the radar grazing angle θ is:
the relationship between the target length and the imaging length is:
and (3) recording an inversion area as E, converting the coordinate system in the step (2) into a polar coordinate system, and then the area A corresponding to the target area is as follows:
in practice, r is much larger than h, so the radar grazing angle θ is a small angle, and the above integral can be directly approximated as the area of a rectangular area on the image:
the radar cross-sectional area of the inversion region is calculated below.
And selecting points in the inversion region in the image, integrating the gray value of the points, and calculating the total echo energy G in the inversion region. It is brought into a scaling function f (x) and converted into a radar cross section area σ of the inversion area:
σ＝f(G)，
the scaling function f (x) is a relational expression obtained by fitting in a previously performed radiometric calibration experiment, and is common knowledge of those skilled in the radar art with respect to radiometric calibration solutions.
Finally, calculating to obtain the average radar cross section area sigma of the sea surface0：
Step 5.3: and calculating the effective wave height of the sea wave.
In step 5.2, the sea surface average radar cross-sectional area σ has been obtained by calculation0. And calculating the effective wave height H of the sea waves by looking up a table 1. The table is the radar grazing angle theta and sigma0And as an input, the effective wave height H of the sea wave is used as an output corresponding relation table, and further, in order to improve the precision, the input parameters can be added with a wind speed parameter.
| Sea wave delta0(dB) | -18 | -11 | -8 | -6 | -4.5 | -2 | 0 |
| Effective wave height (foot) | 0.5 | 1.5 | 4 | 6.5 | 10.5 | 15 | 30 |
TABLE 1
There are two methods for obtaining this correspondence: one approach is to use the data already presented in the relevant literature. If the precision is required to be higher, the precision can be improved through a calibration experiment.
The embodiment of the invention also provides a terminal, wherein a computer program is stored in the terminal, the terminal receives an image sequence, a true course angle sequence and a longitude and latitude coordinate information sequence which are input from the outside, and loads the computer program to execute any one of the wave height calculation methods.
The embodiment of the present invention further provides a wave height measurement system, where the measurement system includes: a radar capable of adjusting a pulse width; the signal acquisition unit is connected with the radar and is used for acquiring an image sequence; the navigation unit can acquire a true course angle sequence and a longitude and latitude coordinate information sequence of the ship; the digital signal processing unit is connected with the signal acquisition unit and the navigation unit and is used for calculating the effective wave height of the sea wave according to the image sequence, the true course angle sequence and the longitude and latitude coordinate information sequence; and
and the display unit is connected with the digital signal processing unit and is used for displaying the effective wave height of the sea waves.
The navigation unit includes: the GPS module and the magnetic compass module are connected with the digital signal processing unit.
Although the present invention has been described in detail with respect to the above embodiments, it will be understood by those skilled in the art that modifications or improvements based on the disclosure of the present invention may be made without departing from the spirit and scope of the invention, and these modifications and improvements are within the spirit and scope of the invention.
Claims (6)
1. A method of calculating the wave height of a sea wave, the method comprising:
adjusting the pulse width of the radar to be minimum, collecting a first image sequence, and recording a first true course angle sequence and a first longitude and latitude coordinate information sequence of the ship;
selecting an image inversion area, and performing inversion area motion compensation;
inverting the sea wave information to obtain the dominant wave wavelength of the sea wave;
adjusting the pulse width of the radar to enable the resolution of the radar to be equal to the main wave wavelength of sea waves, collecting a second image sequence, and recording a second true course angle sequence and a second longitude and latitude coordinate information sequence of the ship;
selecting an image inversion area, and performing inversion area motion compensation;
calculating the sea surface average radar cross section of the inversion area;
and calculating the effective wave height of the sea waves according to the corresponding relation table of the average radar cross section area of the sea surface and the effective wave height of the sea waves.
2. A method of calculating a wave height of ocean waves according to claim 1, wherein the selecting an image inversion region comprises: and rotating the image counterclockwise by a true heading angle by taking the center of the image as an origin to enable the position right above the origin to be in a due north direction.
3. A method of calculating a wave height of ocean waves according to claim 1 wherein the inversion region motion compensation comprises: and determining an image inversion area in the other image according to the selected image inversion area in one image according to the latitude and longitude coordinate difference between the centers of the two images.
4. A method of calculating the wave height of ocean waves according to claim 1, wherein the wave information inversion comprises:
according to the first image sequence, three-dimensional discrete Fourier transform is applied to obtain a three-dimensional wave number frequency spectrum;
based on the gravity wave dispersion equation influenced by Doppler and the basic dispersion relation, the least square method is applied to calculate the flow velocity and the flow direction in an iterative manner;
performing band-pass filtering on the three-dimensional wave number frequency spectrum;
integrating the three-dimensional wave number frequency spectrum subjected to band-pass filtering according to the calculated flow velocity and flow direction and a dispersion equation influenced by Doppler to obtain a radar two-dimensional wave number spectrum;
converting the radar two-dimensional wave number spectrum into a two-dimensional sea wave spectrum by using a modulation transfer function;
and calculating to obtain the dominant wave wavelength of the sea wave according to the two-dimensional sea wave spectrum.
5. A method of calculating a sea wave height as set forth in claim 1, wherein calculating a sea surface average radar cross-sectional area of the inversion region comprises: calculating the area of an inversion region; calculating the radar cross section of the inversion area; and calculating the sea surface average radar cross section of the inversion area.
6. A terminal, wherein a computer program is stored in the terminal, the terminal accepts an externally input image sequence, a true heading angle sequence and a longitude and latitude coordinate information sequence, and the computer program is loaded to execute the wave height calculation method according to any one of claims 1 to 5.
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| CN111624599B (en) * | 2020-05-27 | 2022-12-13 | 哈尔滨工程大学 | Sea wave effective wave height calculation method for sea-going radar inversion |
| CN114779192B (en) * | 2022-06-17 | 2022-09-20 | 中国科学院空天信息创新研究院 | SAR (synthetic aperture radar) field-free calibration method and device, electronic equipment and storage medium |
| CN117033910B (en) * | 2023-09-27 | 2023-12-19 | 宁波麦思捷科技有限公司武汉分公司 | Sea surface high-precision signal processing method and system |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101057139A (en) * | 2004-11-12 | 2007-10-17 | Fmc食品技术股份公司 | An apparatus and method for determining physical parameters in an object using acousto-electric interaction |
| CN101294901A (en) * | 2008-06-10 | 2008-10-29 | 浙江大学 | Method and device for measuring up-conversion time discrimination spectrum |
| CN101639536A (en) * | 2009-08-21 | 2010-02-03 | 中国科学院海洋研究所 | Dual-polarized X-wave band radar ocean wave parameter measurement system |
| CN103080769A (en) * | 2010-09-14 | 2013-05-01 | 松下电器产业株式会社 | Radar device |
| CN105445711A (en) * | 2015-11-27 | 2016-03-30 | 南京信息工程大学 | Sea level essential factor SAR original data simulation method based on inverse Omega-K algorithm |
| CN103969643B (en) * | 2014-05-09 | 2016-09-14 | 哈尔滨工程大学 | One carries out X-band pathfinder inverting ocean wave parameter method based on novel wave dispersion relation band filter |
| CN108680919A (en) * | 2018-03-23 | 2018-10-19 | 海华电子企业(中国)有限公司 | A kind of integrated navigation and wave detecting system based on X-band radar |
| US10259544B2 (en) * | 2012-10-24 | 2019-04-16 | Naiad Maritime Group, Inc. | Predictive sea state mapping for ship motion control |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101853335B (en) * | 2010-06-01 | 2011-12-07 | 国家卫星海洋应用中心 | Point inversion method for ocean surface wind field inversion |
| CN102955152B (en) * | 2011-11-10 | 2014-12-24 | 中国科学院对地观测与数字地球科学中心 | Synthetic aperture radar (SAR) signal simulation method for sea waves |
| US10197667B2 (en) * | 2015-11-13 | 2019-02-05 | Rohde & Schwarz Gmbh & Co. Kg | Method and signal generator for simulation of sea clutter |
| CN109557538A (en) * | 2018-12-26 | 2019-04-02 | 哈尔滨工业大学 | The method for measuring ocean wave parameter with coherent radar based on sea |
-
2019
- 2019-12-10 CN CN201911261340.9A patent/CN111045005B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101057139A (en) * | 2004-11-12 | 2007-10-17 | Fmc食品技术股份公司 | An apparatus and method for determining physical parameters in an object using acousto-electric interaction |
| CN101294901A (en) * | 2008-06-10 | 2008-10-29 | 浙江大学 | Method and device for measuring up-conversion time discrimination spectrum |
| CN101639536A (en) * | 2009-08-21 | 2010-02-03 | 中国科学院海洋研究所 | Dual-polarized X-wave band radar ocean wave parameter measurement system |
| CN103080769A (en) * | 2010-09-14 | 2013-05-01 | 松下电器产业株式会社 | Radar device |
| US10259544B2 (en) * | 2012-10-24 | 2019-04-16 | Naiad Maritime Group, Inc. | Predictive sea state mapping for ship motion control |
| CN103969643B (en) * | 2014-05-09 | 2016-09-14 | 哈尔滨工程大学 | One carries out X-band pathfinder inverting ocean wave parameter method based on novel wave dispersion relation band filter |
| CN105445711A (en) * | 2015-11-27 | 2016-03-30 | 南京信息工程大学 | Sea level essential factor SAR original data simulation method based on inverse Omega-K algorithm |
| CN108680919A (en) * | 2018-03-23 | 2018-10-19 | 海华电子企业(中国)有限公司 | A kind of integrated navigation and wave detecting system based on X-band radar |
Non-Patent Citations (3)
| Title |
|---|
| "Radar Cross-Section Model of the Sea in the Centimeter and Millimeter Waves at Small Grazing Angles";V.I. Lutsenko 等;《Proceedings of the 43rd European Microwave Conference》;20131031;第1381-1384页 * |
| "X波段雷达浪高测量设备参数标定方法";黄健;《科技视界》;20121231(第21期);第19-20页 * |
| "基于航海雷达的海浪遥测关键技术研究";唐艳红 等;《万方数据》;20110215;全文 * |
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