Abstract
Air-to-ground propagation paths are used by many microwave equipments such as sensors, counter-measures and communications. Prediction methods for the coverage of these equipments have been studied elsewhere using powerful numerical modelling techniques. A fundamental consideration is the availability of sufficient and accurate atmospheric data. A review of the possible measurement techniques is given and their suitability for operational use is considered. It is concluded that, in the general case, a high spatial sampling rate is likely to be necessary for any successful exploitation of the prediction methods. The most likely area for application of such methods are open sea-regions where airborne assets with environmental sensors can be freely manoeuvred.