RU2003124710A - PANORAMIC RADAR RADAR METHOD FOR DETERMINING THE STATE OF THE SURFACE LAYER OF AN OCEAN FROM A SATELLITE - Google Patents

Claims (3)

1. 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 Doppler radar equipped with a single-beam rotating antenna with a knife radiation pattern, receiving pulses reflected from the water surface, recording their shape, determining the backscattering cross section σ ₀ and subsequent calculation according to the surface wind speed algorithm V, characterized in that the knife directional pattern These antennas rotate around the vertical axis of symmetry of the antenna passing through its center, the probe pulses are sent to the nadir to the ocean surface, and each pulse illuminates a spot with a size of, for example, 14 × 355 km on the water surface, and when receiving reflected pulses, they use both time and Doppler range selection to highlight in the said spot 14 × 355 km of elementary scattering cells with dimensions, for example, 14 × 14 km, then determine for every two consecutive i-th and i + 1-th cells of the backscattering cross section σ ₀ (θ _i ) and σ ₀ (θ _{i + 1} ), which are adjusted taking into account the Gaussian shape of the antenna pattern in accordance with the expression

where δ _xi is the width of the radiation pattern at the level of 0.5 in power along the sounding direction, θ _i is the angle of incidence for the i-th unit cell, σ ₀ (θ _i ) is the backscattering cross section of the i-th unit cell, then the slope dispersion is determined σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j ) along the azimuthal direction of sounding φ _j for each ith cell

where θ _i and θ _{i + 1} are the angles of incidence for two consecutive unit cells, σ _0к (θ _i ) and σ _0к (θ _{i + 1} ) are the adjusted backscattering cross sections of these cells, respectively, j is the number of the azimuthal direction under which the elementary cell, after which the total variance of the slopes for the ith cell σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ determined from the relation σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ = σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{o}}$ (φ _j ) + σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ , (φ _j + 90 °), and further on the graph of the azimuthal dependence of the slope variance σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j ) determine the propagation direction φ _{wi of} large-scale waves in the i-th cell, and the near-surface wind speed V is determined by the backscattering cross section σ ₀ and the slope dispersions σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j ) and σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j + 90 °) using the algorithm V = F [σ ₀ , σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j ), σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j + 90 °)] obtained by the standard regression method. 2. The panoramic radar method according to claim 1, characterized in that, using additional temporal range selection, elementary cells are formed with dimensions, for example, of the order of 14 × 1 km, then using additional Doppler selection along the azimuthal angle φ _j , elementary cells with with dimensions, for example, of the order of 5 × 1 km. 3. The panoramic radar method according to claim 1 or 2, characterized in that for measuring the average wavelength L _{m of} large-scale waves in each i-th unit cell of the field of view, first the Doppler speeds using additional frequency filters installed in the radar create the starting point counting for registration of reflected pulses in each i-th cell, after that the reception of pulses reflected from the water surface and registration of their shape using the aforementioned time selection is carried out for each i-th cell Using the standard algorithm for the slope at the midpoint of the leading edge of the pulse recorded in the i-th cell, determine the height H of significant waves for several azimuthal directions in the i-th cell, then determine the adjusted value of the height H of significant waves in the i-th cell lanes by determining the average value of the height H from the several measurements mentioned in this cell, and then from the measured maximum value of the slope dispersion σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{w}}$ in the i-th cell on the above graph of the azimuthal dependence of the slope variance σ $\genfrac{}{}{0ex}{}{\text{2}}{\text{i}}$ (φ _j ) and 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 _w .