Calibration of the sampling jitter effect on wind direction measurement from platform-based HF radar

A promising trend in HF systems design for ocean surface mapping application is to change it from the land-based to platform-based. One of the new challenges to be faced is the motion of the platform, which will cause sampling jitter. This paper examines the effects of random jitter in sampling locations in the radar power spectrum, from which wind direction measurements are made. Random jitter leads to, among other distortions, attenuation in power spectral estimation. This is more severe in higher frequencies. The resulting distortion of the radar power spectrum will contribute to error in the direction estimation. To help mitigate this problem, an ensemble average approach is suggested. This can lead to an accurate restoration of the power spectrum if the probability density function of the jitter is known. If the distribution is only partially known, an estimation method is proposed to reliably compute the distribution parameter of the random jitter from the distorted spectrum. Results from simulations illustrate the adverse effects of sampling jitter on the wind direction extraction and demonstrate improvements in recovery of this parameter.