ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa
CURRENT PROBLEMS IN REMOTE SENSING OF THE EARTH FROM SPACE

  

Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2014, Vol. 11, No. 4, pp. 9-16

Physical limitations of accuracy definition of wind speed over the ocean from altimetry data

A.S. Zapevalov1 , V.V. Pustovoytenko1 , K.V. Pokazeev2 
1 Marine Hydrophysical Institute, Sevastopol 299000, Russia
2 M.V. Lomonosov Moscow State University, Moscow 119991, Russia
Errors of wind speed retrieval from altimetry data caused by the influence of different physical processes at the sea surface, not directly related to the wind speed, are considered. These processes lead to ambiguous relationships between characteristics of the sea surface and wind speed, which determines the maximum of altimetry measure-ments precision. The analysis of the restrictions of the determination accuracy of wind speed is carried out on the measurements of sea surface slopes and wind speed made from a spacecraft (Bréon, Henriot, 2006) , as well as on the basis of slopes measurements from the aircraft with wind speed monitoring from a vessel (Cox, Munk, 1954). The effect of scale averaging on the spread of statistical estimates of slopes is discussed. It is shown that the error of wind speed measurements due to ambiguous dependence of the energy of short surface waves on local wind is 0,2 m/s. This error does not depend on the average wind speed. Another kind of errors is due to changes in skewness and kurtosis distributions of the sea surface slopes. This error varies in the range from 0,05 m/s at average wind speed of 1 m/s to 0,4 m/s at average wind speed of 15 m/s.
Keywords: sea surface, satellite altimeter, reflection of radio waves, wind speed measurement
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