TABLE OF CONTENTS As already emphasised, modern Doppler weather radars constitute a significant improvement over conventional weather radars because of the larger number of dimensions of information they provide, in addition to making more accurate measurements. Thus, the primary data products of the Doppler weather radar include wind-velocity-related data regarding each resolution volume in its field of view, besides data on the reflectivity distribution. Typically, the velocity-related data generated by weather radars consist of the mean and the spread of the radial wind speeds within each resolution volume. These data, together with reflectivity, are obtained by suitably processing the amplitudes and phases associated with batches of echo pulses received by the radar. The nature of such signal processing is outlined in this section, as also the structure of Doppler weather radars that make such processing possible.
Refer to Fig. 6.2, which shows a weather radar observing an ensemble of scatterers in the atmosphere. Each scatterer in the resolution volume contributes an echo signal component which appears at the receiver as a complex quantity, with an amplitude and a phase. Since the radar cannot resolve individual scatterers within a resolution volume, the instantaneous signal value sensed or sampled by its receiver is the sum of the echo returns from all the scatterers in the volume, weighted by the antenna pattern function and the receiver response function. Successive samples of the return from a given resolution volume form a complex time...
