Phased array weather radar—benefits and challenges

Possible scientific and operational benefits offered by rapid scan phased array radar technology are identified. Besides providing better detection and warning of hazardous weather, rapid scan radar offers ways to obtain the three dimensional wind field with higher accuracy than possible from conventional Doppler radars. Further, there is the prospect of applying spaced antenna drift techniques to directly estimate transverse winds. In addition, because there is no smearing by the beam, azimuthal resolution is increased, ground clutter canceling is improved, compensation of biases introduced by the ground clutter is better, and recovery of overlaid echoes is easier than is possible with the conventional radar. The beam can be positioned to graze just above the blockage so that rain and low level weather phenomena are optimally viewed. Adaptive and interleaved scans, such as those suited for spectral processing or those needing only moments, can be devised to match the phenomena. Although the technology is quite mature, there are substantial challenges for weather surveillance applications. Expenses are significant and, at the moment, are prohibitive for dual polarization systems. Optimum scanning strategies need to be devised to fully capitalize on beam agility. Furthermore, techniques other than pulse compression need to be developed. We will communicate our current thoughts about these and other benefits and challenges.