RU2449312C1 - Panoramic radar method of determining parameters of state of ocean surface layer from satellite - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: knife-edge beam of the antenna is rocked relative the vertical in a direction perpendicular to the direction of motion and each probe pulse is used to illuminate a 14x355 km spot on the water surface (at altitude of 800 km). Reflected pulses are received using time gating on the range based on the Doppler shift sign to select in said 14x355 km spot elementary scattering cells (ESC) measuring, for example, 14x14 km. Using a synthesis procedure along the direction of motion of the satellite, the backscattering section is determined and the water surface slope dispersion in each ESC is reconstructed. Further, by selecting the azimuth angle, the water surface slope dispersion along said direction is reconstructed and, by analysing the azimuth dependency of slope dispersion in each ESC, the direction of wave propagation in each cell is determined. The speed of surface wind V in each ESC is determined using an algorithm obtained using a regression method. In a special case of the method, average values of the rough sea and wavelength of a big wave are also determined.

EFFECT: high accuracy of determining parameters of the state of the ocean surface layer.

2 cl, 2 dwg

Description

The invention relates to radar, and in particular to radar methods for determining the parameters of sea waves, and can be used in meteorology and oceanology for remote monitoring of the state of the surface layer of the oceans from a satellite.

водной поверхности и направление распространения крупномасштабного волнения φ_wi, а также восстановить в каждой ячейке скорость ветра V.Providing on-line monitoring of the state of the near-surface layer of the ocean from a satellite in the widest possible viewing range is important for making reliable weather forecasts, monitoring global climate changes, ensuring life safety in coastal areas, studying the World Ocean, and solving many other problems. Moreover, for truly operational monitoring, it is desirable to ensure the construction with a sufficient spatial resolution of a two-dimensional image of the water surface, for which it is necessary to determine (restore) in each “i” th unit cell of the field of view the slope variance

water surface and the direction of propagation of large-scale waves φ _wi , as well as restore wind speed V in each cell.

морской поверхности, которая в свою очередь зависит от присутствия волн зыби, не связанных с ветром в точке измерения. По наклону переднего фронта каждого принятого импульса определяют высоту Н значительного волнения в освещенном пятне. Принятые последовательности импульсов для 2-6 лучей обрабатывают, как в самолетном измерителе спектра волн, однако перенос данного радиолокатора на спутник существенно ухудшает его пространственное разрешение, поскольку позволяет измерять лишь спектр волн, длина которых более 70 м, а высота - более 2 м, т.е. теряется информация о высоте и наклонах волн короче 70 м. К недостаткам данного способа относится и то, что в основу всех расчетов положено предположение об однородности волнения в пятне (элементе разрешения) с радиусом 88 км, что является некорректным с точки зрения океанологов, поскольку современные стандартные модели открытого океана используют сетку с элементом разрешения (элементарной ячейкой) для открытого океана 50×50 км и для прибрежных районов 28×28 км (см., например, «Satellites, Oceanography and Society», ed. by D.Halpem. Elsevier, Amsterdam, p.35-56, 2000).A known method for determining the parameters of a water surface from a satellite is a radar equipped with an antenna with a multipath (6 rays) radiation pattern (C. Tison, D. Hauser, G. Carayan et al. A spaceborne radar for directional wave spectrum estimation: first performance simulations. IGARSS'08). This method consists in the fact that using a multi-beam antenna emit independent sequences of short probe pulses in different directions: the first beam (a sequence of pulses) is directed along the normal (i.e. to nadir) to the underlying water surface, the direction of the second beam is 2 ° relation to the first ray, etc. The last ray is directed at 10 °. Rays 2 through 6 rotate around a vertical axis as the satellite moves. On the water surface, the rays illuminate spots (leave a mark) with characteristic sizes of approximately 17.7 × 17.7 km, and the distance between the spots (i.e., the radius of the area from which information is collected) at a satellite orbit altitude of about 500 km is 88 km . The part of the power of each probe pulse of all rays reflected back from the water surface is received by the corresponding antenna and the shape of the received reflected pulses is recorded. During communication sessions, this information is transmitted to a tracking station, where the received pulses are processed using a computer. The received sequence of pulses of the first beam is processed according to well-known algorithms used in satellite altimeters (see, for example, Alfred R. Zieger et al. NASA Radar Altimeter for TOPEX / POSEIDON Project, Proceedings of the IEEE, Vol. 79, No. 6, June 1991 ) The maximum value of the received power P _{max of} each reflected pulse (by the shape of the pulse) determines the backscattering cross section σ ₀ , which determines (restores) the velocity V of the surface wind. In this case, the wind speed V is restored with a systematic error due to the ambiguity of the relationship between the reflected power P _max and the wind speed V, since it is known that the reflected power also depends on the variance of the slopes

sea surface, which in turn depends on the presence of swell waves not associated with the wind at the measurement point. The slope of the leading edge of each received pulse determines the height H of significant excitement in the illuminated spot. The received pulse sequences for 2-6 beams are processed as in an airplane wave spectrum meter, however, the transfer of this radar to the satellite significantly reduces its spatial resolution, since it only measures the wave spectrum with a length of more than 70 m and a height of more than 2 m, t .e. information on wave heights and inclinations shorter than 70 m is lost. The disadvantages of this method include the fact that all calculations are based on the assumption that the waves are uniform in a spot (resolution element) with a radius of 88 km, which is incorrect from the point of view of oceanologists, since modern standard open-ocean models use a grid with a resolution element (unit cell) for the open ocean 50 × 50 km and for coastal areas 28 × 28 km (see, for example, “Satellites, Oceanography and Society”, ed. by D. Halpem. Elsevier Amsterdam, p. 35-56, 2000).

Closest to the claimed method according to its technical essence, it is a panoramic radar method for determining the variance of the slopes of the water surface, the direction of propagation of large-scale waves and the speed of the surface wind above the water surface from the satellite using a radar with a knife antenna pattern rotating around a vertical axis during flight, which is selected as a prototype (RF patent No. 2274877, IPC ⁷ G01S 13/95, published on 04/20/2006). The prototype method consists in the fact that using a single-beam rotating antenna with a knife radiation pattern, i.e. narrow (1-2 °) along one axis and wide (20-25 °) in the perpendicular direction, probe the sea surface at a zero angle of incidence, which corresponds to angles of incidence of about -12 to 12 ° within the antenna pattern. This allows you to get a wide (about 350 km at a flight altitude of 800 km) viewing range, i.e. to carry out a panoramic mode of operation of the radar. The same radar antenna receives a sequence of reflected pulses, using a recording device to record their shape and transmit information to the tracking station. To process the received information, Doppler or temporal range selection is used, with the help of which a resolution element is formed, for example, 14 × 14 km. To restore the wind speed, a two-parameter algorithm is used that describes the dependence of the wind speed on the backscattering cross section and on the slope dispersion, which is obtained by regression analysis of satellite data on the backscattering cross section σ ₀ , the reconstructed slope dispersion of the water surface and buoy data on the corresponding surface velocities wind V.

The disadvantage of the prototype method is that when the antenna rotates, each elementary scattering cell is not observed all the time, but only at 6 azimuthal angles (at a speed of 6 revolutions per minute). This leads to a high noise level due to insufficient averaging.

водной поверхности, направления распространения φ_wi крупномасштабного волнения, а также более точное восстановление скорости V приповерхностного ветра за счет увеличения времени наблюдения за каждой элементарной рассеивающей ячейкой.The problem to which the present invention is directed, is the development of a panoramic radar method for determining the state of the surface layer of the ocean, which provides more accurate than in existing methods, measurement in each "i" -th elementary scattering cell of a wide viewing band of the following parameters: slope dispersion

water surface, the propagation direction φ _{wi of} large-scale waves, as well as a more accurate restoration of the surface wind speed V by increasing the observation time for each elementary scattering cell.

и направления распространения крупномасштабного волнения φ_wi в каждой «i»-й элементарной рассеивающей ячейке, а также последующее вычисление скорости приповерхностного ветра V по полученному методом регрессии алгоритму.The technical result in the developed method is achieved by the fact that, as in the prototype method, the sounding pulses of the microwave range are emitted by a coherent Doppler radar equipped with a single-beam antenna with a knife beam pattern, receiving the sounding pulses of the microwave range reflected from the water surface, registering their shape, highlighting using temporal range selection, taking into account the sign of the Doppler shift from the spot illuminated by each probe pulse in the water surfaces with dimensions, for example, 14 × 355 km of elementary scattering cells with dimensions, for example, 14 × 14 km, determination of the backscattering cross section, the dispersion of the slopes of the water surface

and the direction of propagation of large-scale waves φ _wi in each “i” th elementary scattering cell, as well as the subsequent calculation of the surface wind velocity V according to the algorithm obtained by the regression method.

, при этом дисперсию наклонов

поверхности в направлении полета определяют из соотношения

, где δ - ширина (в радианах) диаграммы направленности антенны на уровне 0,5 по мощности; σ_0у - сечение обратного рассеяния, полученное при синтезировании; σ_0,max - сечение обратного рассеяния, соответствующее центральной области освещенного пятна.What is new in the developed method is that the knife antenna pattern oriented along the flight direction is pumped relative to the vertical in the direction perpendicular to the direction of motion, and for determining the backscattering cross section and the dispersion of the slopes of the water surface along the direction of motion for each elementary scattering cell, they are used within each illuminated the next probing pulse of the spot on the water surface in a wide field of view of the synthesis procedure, consisting that for each «i» th unit of the scattering cell at successive times for the time of observation it is determined the angle of incidence and the corresponding backscatter cross section σ _i, then the processing of information collected during said successive time measuring backscatter cross sections σ _i The "i" -th elementary scattering cell is transformed into simultaneous observation of the same "i" -th elementary scattering cell on the whole mentioned spot at different angles, thereby synthesizing echenie backscatter σ _0y entire illuminated spot in the hypothetical case agitation, uniform within the whole of this spot,

while the variance of the slopes

surfaces in the direction of flight are determined from the relation

where δ is the width (in radians) of the antenna pattern at the level of 0.5 in power; σ _0y is the backscattering cross section obtained by synthesis; σ _{0, max} is the backscattering cross section corresponding to the central region of the illuminated spot.

в «i»-й элементарной рассеивающей ячейке на графике азимутальной зависимости дисперсии наклонов

и по уточненному значению высоты Н значительного волнения среднюю длину волны L_m крупномасштабного волнения определяют из соотношения L_m=H/σ_Sm.In the particular case of the method of measuring the average wavelength L _{m of} large-scale waves in each "i" -th elementary scattering cell of the field of view, first using Doppler velocities using additional frequency filters installed in the Doppler radar, an initial reference point is created for recording reflected pulses in each "I" -th elementary scattering cell, after which the reception of pulses reflected from the water surface and registration of their shape using the aforementioned temporary selection is carried out for I of each "i" -th elementary scattering cell separately and using the standard algorithm for the slope at the midpoint of the leading edge of the pulse recorded in this "i" -th cell, determine the height H of significant waves for several azimuthal directions in this "i" - -th cell, then determine the specified value of the height H of significant waves in the "i" -th elementary scattering cell of the bandwidth by determining the average value of the height H for several of the measurements in this cell, and then measured th maximum value of the dispersion slope

in the “i” th elementary scattering cell on the graph of the azimuthal dependence of the slope dispersion

and according to the specified value of the height H of significant waves, the average wavelength L _{m of} large-scale waves is determined from the relation L _m = H / σ _Sm .

The method is illustrated by the following figures.

Figure 1 presents a variant of a block diagram of a device for implementing the developed method.

Figure 2 shows an example of dividing the span into elementary scattering cells inside the illuminated spot.

The block diagram of a device for implementing the developed method, is shown in figure 1, contains a single-beam antenna 1 with a knife radiation pattern, which is connected through a block of electronic scanning scanning of the radiation pattern 2 to a coherent Doppler radar 3, which in turn is connected to a recording device 4, the output of which is connected to the input of the transceiver 5, which provides communication with a tracking station (not shown) on Earth. In this case, the control of all elements of the device for implementing the developed method is carried out using block 6, which has a connection with the electronic control unit for scanning the radiation pattern 2, with a coherent Doppler radar 3, a recording device 4 and a transceiver 5.

As a single-beam antenna 1 with a knife radiation pattern, for example, a phased antenna array developed by the Scientific Research Institute of TP (Moscow) can be used. In this case, the swing mode is controlled electronically. Also, to implement the developed method, a single-beam slit antenna MIUS of domestic production or a single-beam slot antenna PR-5 of Czech manufacture (TESLA) can be used. Here, the knife radiation pattern of the antenna is provided by selecting the size of the slit, for example, a knife radiation pattern with angular dimensions of 1 ° × 25 ° can be formed. In this case, the swing mode in the direction perpendicular to the direction of movement is carried out mechanically.

At a flight altitude of 800 km, such an antenna illuminates a spot on the surface of the ocean with dimensions of 14 × 355 km. The scanning frequency relative to the vertical axis occurs, for example, with a frequency of 0.5 Hz.

As a coherent Doppler radar 3 can be used, for example, a Doppler speed and drift meter DIIS (Kamensk-Uralsky) or Doppler radar manufactured at the Research Institute of TP Moscow. As the recording device 4 and the transceiver 5, any standard devices of a similar purpose, currently used by satellites to record information and transmit it to Earth, can be used.

The developed panoramic radar method for determining the state parameters of the surface layer of the ocean is as follows.

During the flight of the satellite over the ocean, through a single-beam antenna 1 with a knife radiation pattern controlled by the electronic scanning control unit of the radiation pattern 2 and a coherent Doppler radar 3, controlled by block 6, a sequence of probe pulses is emitted along the normal to the water surface. When swinging a knife radiation pattern with the indicated angular dimensions of 1 ° × 25 ° and a swing frequency of 0.5 Hz on the water surface, a 355 km wide field of view is illuminated (for a specified flight altitude of 800 km), which allows an image of the process occurring on the ocean surface to be obtained. Moreover, each individual radiation pulse of a coherent Doppler radar 3 illuminates at a specified flight altitude a spot with dimensions of the order of 14 × 355 km. Using the same single-beam antenna 1 with a knife beam pattern and a coherent Doppler radar 3, a sequence of pulses reflected from the water surface is received, which are processed and stored in the recording device 4 before the next communication session with the tracking station on Earth. Using the transmitting and receiving device 5, information is exchanged with the tracking station, while the received commands are sent to block 6, with which they coordinate the operation of the entire device to implement the developed method.

Processing with the help of a recording device 4 of the probe pulses reflected from the water surface consists in the fact that using the temporary selection in range, taking into account the sign of the Doppler shift, each mentioned spot is illuminated, illuminated by a separate probe pulse, with dimensions 14 × 355 km into elementary “i” - e (i varies from 1 to N) scattering cells, i.e. the division of the illuminated spot is carried out along the Y axis for each angle of incidence (see figure 2).

The use instead of rotating the antenna around the vertical axis (as in the prototype method) of the swing mode of the antenna pattern in a direction perpendicular to the direction of movement, with a range of, for example, ± 12 °, gives the proposed method significant advantages.

For example, with a 355 km field of view for a satellite flight height of 800 km and a radiation pattern of 1 ° × 25 °, the elementary scattering cell has a size of 14 × 14 km (the size of the elementary scattering site depends on the problem being solved and can vary widely) and is formed by the radiation pattern antennas (along the X axis) and using temporal range selection taking into account the sign of the Doppler shift (along the Y axis). If we set the step along the angle of 1 ° inside the radiation pattern, then for the width of the radiation pattern of 25 ° we get 25 elementary cells 14 × 14 km in size. At a sweep (scan) frequency of 0.5 Hz, each cell will be observed for approximately 0.1 s, which corresponds to the correlation time of the signal reflected by the sea surface. For 2 s, the radar is shifted by about 14 km, which corresponds to the size of the elementary scattering area, and thus there is an “overview” of the entire reflecting surface without gaps, which eliminates the problem of insufficient averaging of the measured values.

In addition, since measurements are carried out for each elementary scattering cell at all angles of incidence within the antenna pattern, then in the process of processing the information obtained by this method, the algorithms developed for both a stationary and a rotating antenna are applicable. In this case, the advantages of a fixed antenna associated with the original synthesis procedure along the flight path and the capabilities of a radar with a rotating antenna with a wide field of view are used. The processing algorithms are based on different principles, and comparing the results of reconstructing the variance of the slopes of the water surface using one or the other algorithms makes it possible to control their effectiveness, and also to exclude from consideration and processing sharp fluctuations in the values of the measured quantities that “fall out” of the overall picture of observations and are caused by accidental interference, such as meteorological, or power failure.

Thus, the processing of the reflected signal and the restoration of the wave parameters is carried out in accordance with certain algorithms.

When analyzing cells along the Y axis (along the direction of movement), an algorithm developed for a fixed knife antenna is used (see Karaev V.Yu., Kanevsky MB Radar method for determining the state parameters of the surface layer of the ocean. - RF Patent No. 2235344, IPC ⁷ G01S 13/95, published on 06/03/2002), oriented along the direction of flight, and carry out the synthesis procedure.

. В результате выполнения такой процедуры синтезирования суммирующее изображение будет аналогично «одномоментному» наблюдению поверхности океана в освещенном пятне, но с однородным волнением в пределах всего этого пятна. При этом дисперсия наклонов поверхности

в направлении полета определяется по следующей формуле:Within each scattering cell with dimensions, for example, 14 × 14 km, the waves can be considered homogeneous. The backscattering cross section σ _{i of} each scattering “i” -th cell is periodically calculated during the entire time it is in the satellite’s visibility range, while a single-beam antenna 1 with a knife beam pattern of a coherent Doppler radar 3 sees an “i” cell at different times surfaces at different angles of incidence θ. If we take into account the stationary state of the waves at the measurement times and combine all the data on the backscattering cross section of the “i” th cell obtained over the entire time of its observation at different time instants (or at different incidence angles), then we determine the backscattering cross section σ _0у obtained at measurement by coherent Doppler radar 3 with a single-beam antenna 1 with a knife radiation pattern in a hypothetical case of waves uniform throughout the entire mentioned spot

. As a result of such a synthesis procedure, the summing image will be similar to “instantaneous” observation of the ocean surface in a lighted spot, but with uniform excitement within the entire spot. In this case, the dispersion of the surface slopes

in the direction of flight is determined by the following formula:

,

,

where δ is the width (in degrees) of the radiation pattern of a single-beam antenna 1 with a knife radiation pattern at the level of 0.5 in power; σ _0y is the backscattering cross section obtained by synthesis within the illuminated spot, σ _{0, max} is the backscattering cross section corresponding to the central region of the illuminated spot

If a straight line at an angle φ _{wi is} drawn from an elementary scattering cell located on the flight path (see Fig. 2), then for cells located along this straight line, a processing algorithm developed for a radar with a rotating antenna can be applied (see Karaev V .Yu., Kanevsky MB Panoramic radar method for determining the state parameters of the surface layer of the ocean from a satellite. - Patent of the Russian Federation No. 2274877, IPC ⁷ G01S 13/95, published on 04/20/2006). In this case, the fact that neighboring elementary scattering cells differ in the angle of incidence along the selected direction is used.

For each “i” th cell, the reflected signal power and the backscattering cross section σ _i (θ _i ) are determined, where θ _i is the angle of incidence of the probe radiation on the “i” th cell. This information is stored in the recording device 4 until the communication session with the tracking station. Then, at the tracking station, correction is carried out according to the power of the received signal from each “i” th cell, taking into account the shape of the radiation pattern of a single-beam antenna 1, which is accepted as Gaussian. If for convenience of consideration we introduce the axis X ₁ directed along the selected azimuthal angle φ and the axis Y ₁ perpendicular to the axis X ₁ , the shape of the radiation pattern of a single-beam antenna 1 is given by the following expression:

,

,

where δ _x and δ _y are the width of the radiation pattern at the level of 0.5 in power along the axes X ₁ and Y _1, respectively, R ₀ is the height of the satellite. For correction, multiply the power of the reflected signal in the “i” th unit cell (backscattering cross section σ _i ) by a coefficient associated with the directivity pattern of a single-beam antenna 1. The recalculation formula has the following form:

.

.

After performing the correction, the variance of the slopes along the sounding direction (axis X ₁ ) is calculated by the following formula:

,

,

where θ _i and θ _{i + 1} are the angles of incidence for two consecutive “i” and “i + 1” th unit cells along the sounding direction (azimuthal angle φ _j ); σ _0к (θ _i ) and σ _0к (θ _{i + 1} ) are the adjusted backscatter cross sections of these cells, respectively, j is the azimuthal direction number under which each unit cell is observed.

As can be seen from the above formula (in the denominator of the formula, the backscattering cross section σ _0к (θ _{i + 1} ) in the “i + 1” cell is divided by the backscattering cross section σ _0к (θ _i ) in the “i” th cell), for Processing the experimental data from the satellite is important (used) not the absolute values of the reflected power (cross-section of backscattering) in each elementary reflecting cell, but the relative changes in the reflected power in neighboring cells. Due to this, in the developed method, it is possible to get rid of such significant problems as the need for regular radar calibration by power, the need to take into account the attenuation of the reflected signal by rain clouds, the need to maintain stable radar power over the entire life cycle.

поверхности в каждой «i»-й элементарной ячейке измеряют дисперсию наклонов в этой ячейке под разными азимутальными углами φ_j. Таким образом, определив дисперсию наклонов для двух взаимно перпендикулярных направлений, определяют полную дисперсию наклонов для «i»-й ячейки

из соотношения:

.It is known that, with a sufficient degree of accuracy, the total variance of the slopes of the surface is the sum of the variances of the slopes measured in two mutually perpendicular directions. Therefore, to determine the total variance of the slopes

the surfaces in each “i” th unit cell measure the variance of the slopes in this cell at different azimuthal angles φ _j . Thus, by determining the variance of the slopes for two mutually perpendicular directions, determine the total dispersion of the slopes for the "i" -th cell

from the ratio:

.

определена для нескольких (разных) азимутальных углов φ_j, то по экспериментально измеренным точкам с помощью алгоритма, используемого в скаттерометрии, восстанавливают азимутальную зависимость дисперсии наклонов. Максимальное значение дисперсии

на данном графике указывает искомое направление распространения крупномасштабного волнения φ_wi в «i»-й ячейке.The next step in data processing is to determine the propagation direction φ _{wi of} large-scale waves in the "i" -th cell. Since in each “i” th cell the slope dispersion

is determined for several (different) azimuthal angles φ _j , then the azimuthal dependence of the slope dispersion is restored from the experimentally measured points using the algorithm used in scatterometry. The maximum value of the variance

on this graph indicates the desired direction of propagation of large-scale waves φ _wi in the "i" -th cell.

и

. Для вычисления искомой скорости ветра V используют регрессионный алгоритм

, который должен быть получен на начальном этапе калибровки радиолокатора по стандартной методике (см., например, Witter and Chelton. A Geosat altimeter wind speed algorithm and a method for altimeter wind speed algorithm development. J. Geophysical Research, v.96, NC5, 1995, p.8853-8860) с учетом упомянутых измеренных дисперсий наклонов

и

. Дисперсии наклонов

и

зависят не только от скорости ветра V, но и от присутствия в «i»-й ячейке волн зыби, не связанных с ветром в данной ячейке, но влияющих на связь сто со скоростью ветра V. Методика получения регрессионного алгоритма известна (см., например, Г.Корн и Т.Корн. Справочник по математике для научных работников и инженеров. М.: Наука, 1977 г., стр.553-557).The surface wind speed V in the “i” th cell is determined by the backscattering cross section σ _i measured with a recording device 4 in each cell and the slope dispersions measured in mutually perpendicular directions in each cell

and

. To calculate the desired wind speed V using a regression algorithm

, which should be obtained at the initial stage of radar calibration using a standard method (see, for example, Witter and Chelton. A Geosat altimeter wind speed algorithm and a method for altimeter wind speed algorithm development. J. Geophysical Research, v. 96, NC5, 1995, p.8853-8860) taking into account the mentioned measured slope variances

and

. Slope Dispersions

and

depend not only on the wind speed V, but also on the presence in the "i" -th cell of swell waves that are not related to the wind in this cell, but affect the connection of one hundred with wind speed V. The technique for obtaining the regression algorithm is known (see, for example , G. Korn, and T. Korn, A Handbook of Mathematics for Scientists and Engineers, Moscow: Nauka, 1977, pp. 553-557).

«i»-й ячейке на графике азимутальной зависимости дисперсии наклонов

и по уточненному значению высоты Н значительного волнения определяют среднюю длину волны L_m крупномасштабного волнения из соотношения L_m=H/σ_Sm. Высота H и длина волны L_m крупномасштабного волнения имеют важное значение для численных моделей приповерхностного слоя океана, кроме того, от длины волны L_m напрямую зависит скорость распространения крупномасштабного волнения, т.е., например, насколько быстро зародившийся шторм достигнет прибрежной зоны.In the particular case of the implementation of the developed method, when it is necessary to measure the average wavelength L _{m of} large-scale waves in each unit “i” cell with dimensions, for example, 14 × 14 km, first by Doppler velocities using additional frequency filters installed in the reception path of the coherent Doppler radar 3, create an initial reference point for recording reflected pulses in each "i" -th cell. After that, the reception of pulses reflected from the water surface and registration of the time dependence of the reflected signal power (finding the pulse shape) is carried out separately for each “i” th cell and using the standard algorithm for the slope at the midpoint of the leading edge of the pulse recorded in “i” -th cell, determine the height H of significant excitement for several azimuthal directions in the "i" -th cell. Then determine the adjusted value of the height H of significant excitement in the "i" -th cell by determining the average value of the height H by several measurements in this cell. After which, according to the aforementioned measured maximum value of the slope dispersion

“I” -th cell in the graph of the azimuthal dependence of the slope variance

and from the updated value of the height H of significant waves, determine the average wavelength L _{m of} large-scale waves from the relation L _m = H / σ _Sm . The height H and the wavelength L _{m of} large-scale waves are important for numerical models of the surface layer of the ocean, in addition, the propagation velocity of large-scale waves, i.e., for example, how quickly the storm begins to reach the coastal zone, directly depends on the wavelength L _m .

Thus, the developed panoramic radar method for determining the state parameters of the surface layer of the ocean makes it possible to construct a two-dimensional image of the water surface, which opens up possibilities for analyzing wave processes on the ocean surface, studying their structure and temporal dynamics during repeated observations, which is necessary for making long-term weather forecasts, for studying the oceans and solving many other applied problems.

Claims (2)

1. A panoramic radar method for determining the state parameters of the surface layer of the ocean from a satellite, comprising emitting microwave sounding pulses with a coherent Doppler radar equipped with a single-beam antenna with a knife beam pattern, receiving microwave sounding pulses reflected from the water surface, registering their shape, extracting them using a time range selection taking into account the sign of the Doppler shift from illuminated by each probe pulse stains on the water surface with the size, e.g., 14 × 355 km scattering elementary cell with dimensions, for example, 14 × 14 km, determining the backscattering cross section σ _i, dispersion slopes of the water surface

and the direction of propagation of large-scale waves φ _wi in each "i" -th elementary scattering cell, as well as the subsequent calculation of the surface wind speed V according to the regression algorithm, characterized in that the knife antenna pattern oriented along the flight direction is pumped relative to the vertical in the direction perpendicular to the direction of motion, and to determine the cross section for backscattering and dispersion of the slopes of the water surface along the direction of motion for each electric within each wide spot band illuminated by the next sounding pulse, a synthesis procedure is used that consists in the fact that for each "i" -th elementary scattering cell, the angle of incidence of radiation is determined at consecutive time points for the entire time of its observation and the corresponding backscatter cross section σ _i, then the processing of information collected during said successive time measuring sections backscatter σ _{i «i»} th ale succinic scattering cell transformed in cross-sectional observation of the same «i» -th elementary scattering cell for all said illuminated spot at different angles, thereby synthesizing section backscatter σ _0y entire illuminated spot in the hypothetical case agitation, uniform within the whole of this spot,

while the variance of the slopes

surfaces in the direction of flight are determined from the relation

where δ is the width (in radians) of the antenna pattern at the level of 0.5 in power; σ _0y is the backscattering cross section obtained by synthesis, σ _{0, max} is the backscattering cross section corresponding to the central region of the illuminated spot. 2. The panoramic radar method according to claim 1, characterized in that for measuring the average wavelength L _{m of} large-scale waves in each "i" -th elementary scattering cell of the viewing band at first by Doppler speeds using additional frequency filters installed in the Doppler radar, create an initial reference point for recording the reflected pulses in each "i" -th elementary scattering cell, after which the reception of pulses reflected from the water surface and registration of their shape using the aforementioned belt selection is carried out for each "i" -th elementary scattering cell separately and the standard algorithm for the slope at the midpoint of the leading edge of the pulse recorded in this "i" -th cell, determine the height H significant waves for several azimuthal directions in this " i "-th cell, then determine the adjusted value of the height H of significant waves in the" i "-th elementary scattering cell of the field of view by determining the average value of the height H from several of these measurements in this cell, after which the measured maximum value of the dispersion slope

in the “i” th elementary scattering cell on the graph of the azimuthal dependence of the slope dispersion

and according to the specified value of the height H of significant waves, the average wavelength L _{m of} large-scale waves is determined from the relation L _m = H / σ _Sm .

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