6/9/2023 0 Comments Indirection bandThe backscattered signal varies according to the wind speed and its effects on ocean roughness. ![]() Scatterometers are radars and send pulses of radiation at the surface. The only exception is 'RapidSCAT', which is a scatterometer on the international space ship (ISS). Nowadays scatterometer data is operationally used especially for data assimilation and for marine nowcasting.įigure 8 shows an overview of the current and proposed satellite missions carrying scatterometers.įigure 8: Overview of finished, current and proposed satellite missions with scatterometeres onboard. However, widespread usage of scatterometers started in the 1990s. Scatterometry started in the 1970s – the first satellite with a scatterometer onboard was Seasat-A (NASA). It took some 20 more years to discover that this noise was related to wind velocity. Sensitive to rain, coastal coverage - Land contaminationĭuring World War 2 it was discovered that radars also picked up some kind of clutter over the oceans. Less detection in the higher wind range (> 60 kt), sea ice, coastal coverage - Land contamination Table 2: Comparison of C-band and Ku-band scatterometers. Thus, Ku-band radars with a wavelength of about 2 cm are sensitive to rain. The wavelength of the radar is chosen according to the sampling scale. The two radar types are compared with each other in Table 2. A Geophysical Model Function (GMF) provides the radar cross section as a function of the equivalent neutral wind vector at 10 m anemometer height (not the actual wind!), incidence angle, relative azimuth angle, radar frequency, and polarization.ĭepending on the wavelength of the radiation a distinction can be made between C-band and Ku-band scatterometers. Scatterometers measure the radar cross section of the ocean surface. It has become an increasingly important tool for monitoring climate, forecasting (marine) weather and studying the atmosphere-ocean interactions. Spaceborne wind scatterometry is an indirect method of measurement. They are used by low Earth orbiting satellites and act like radars: they transmit electromagnetic pulses and detect the backscattered signals. Scatterometers are active remote sensing instruments for deriving wind direction and speed from the roughness of the sea.
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