An Algorithm for Estimation of Wave Height From Shadowing in X-Band Radar Sea Surface Images

Directional wave spectra and integrated wave parameters can be derived from X-band radar sea surface images. The calibration of such spectra has until now depended on various empirical and semiempirical methods, which also require an external reference increasing the total expenses of operation. A novel algorithm, which is fully based on theory, producing reasonable estimates of the significant wave height based on shadowing in the images, has been now developed. The method does not require any reference measurements, and with that, enables automatic calibration of spectra from radar sea surface images, as well as the potential for reduced operational cost and increased accuracy of such wave-monitoring systems. Promising results are obtained with data acquired at a test site in the North Sea. Further work is, however, required to refine the algorithm and to test it under varying circumstances at various sites.