Crossbeam, wind measurements with phased array Doppler weather radar: Theory

Doppler weather radars measure only the radial wind component of wind, and thus are limited in providing accurate information of damaging wind potential. The use of a phased array antenna opens the possibility that crossbeam winds can also be measured. This paper examines and compares two alternatives whereby a phased array weather radar can measure crossbeam winds. The theoretical accuracy of the quasi-horizontal component of the crossbeam wind for each of these alternatives is shown to be strongly dependent on turbulence intensity. Crossbeam winds can be measured with accuracies on the order of 2 m s(-1) in less than 10 s if turbulence intensity is less than 1 m s(-1).