An Evaluation of the Accuracy of Some Radar Wind Profiling Techniques

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  • 1 National Severe Storms Laboratory, Norman, OK 73069
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Abstract

Advances in clear air Doppler radar measurement have made practical the monitoring of radial velocities in the troposphere and lower stratosphere and even the vector wind, under some assumptions. Because the objective of wind profiling is to monitor winds representative of larger scale atmospheric motions, an assumption of a time-invariant spatially uniform wind field is commonly used. Then, the accuracy of the wind estimators depends on the error variance of the radial velocity, the departure from uniformity of the wind field and the measurement geometry.

We derive expressions for the variance and bias for some of these estimators when applied to a spatially linear wind field. The techniques we consider are three fixed beams, azimuthal scanning (VAD) and elevation scanning (VED). In addition, we examine a method based on the integration of the continuity equation to estimate the areal-averaged wind. This technique sometimes leads to better estimates than do direct methods.

Abstract

Advances in clear air Doppler radar measurement have made practical the monitoring of radial velocities in the troposphere and lower stratosphere and even the vector wind, under some assumptions. Because the objective of wind profiling is to monitor winds representative of larger scale atmospheric motions, an assumption of a time-invariant spatially uniform wind field is commonly used. Then, the accuracy of the wind estimators depends on the error variance of the radial velocity, the departure from uniformity of the wind field and the measurement geometry.

We derive expressions for the variance and bias for some of these estimators when applied to a spatially linear wind field. The techniques we consider are three fixed beams, azimuthal scanning (VAD) and elevation scanning (VED). In addition, we examine a method based on the integration of the continuity equation to estimate the areal-averaged wind. This technique sometimes leads to better estimates than do direct methods.

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