TABLE OF CONTENTS Doppler weather radars are beginning to play the central role in the sensing of weather phenomena in the evolving and futuristic scenarios of aviation management and safety enhancement. However, it must be remembered that Doppler weather radars are elaborate and expensive equipment which cannot be installed everywhere, and there will always be a considerable amount of aviation activity that will not have the benefit of these radars to the required degree. In terms of gross area, of course, weather radar coverage may be available over most parts of many countries in the foreseeable future, but the data from such radar networks will not meet the stringent requirements of aviation support, especially in terminal areas, over the entire zone of coverage. In particular, the data adequacy and quality with respect to low-altitude coverage (because of radar horizon limitations) and resolution, which are dependent on the distance from the radar, will be highly nonuniform over the coverage zone. Further, the multipurpose weather radars used for network coverage of large areas will not, in general, provide the data update rates and the high-level and special-purpose software capabilities required for supporting modern and future aviation. This fact, together with the limitations on the number of dedicated radars with sophisticated aviation weather surveillance capability (such as the TDWR and ASR-9), means that significant aviation activity will remain outside the type of weather radar coverage that provides important information such as low-altitude divergence and wind shear.
There is thus need for additional instrumentation which...
