The calculation algorithm for average wind speed and direction in prediction technology of OTH radar detection range

Radar may realize b-Los detection when electromagnetic wave propagation trapped in evaporation duct. When predicting the OTH radar detection range, the parameter of atmospheric wind speed and direction are badly needed in the processes of calculating atmospheric refractivity profile and the loss of electromagnetic propagation. P-J model is used to study the effect of wind speed to evaporation duct height. Parabolic equation is used to study the effect of wind speed to loss of electromagnetic propagation under the condition of evaporation duct atmosphere. Three algorithm including scalar, unit vector and vector are introduced and are compared in prediction of radar detection range by experiment on the sea. The result shows that average wind speed and direction calculated by unit vector has a better result than the others in predicting radar detection range.