Physically-based multiparameter radar simulation, and comparison with radar measurements

There is a growing use of multiparameter radars for the observation of the atmosphere, and in particular for the remote sensing of rain. Radar systems have the undeniable advantage of being able to monitor very large areas with a single installation, in real time.

On the other hand their measurements are often quite "delicate"; the conversion of the radar measurables into meteorological quantities (like rain rate) is not unique, depending – for example - on the model assumed for the target, on the vertical profile of reflectivity, etc. In this context, the availability of sophisticated radar simulators can prove to be extremely useful to try and discriminate the effect of the different contributions on the received echoes.

In this work a physically-based multiparameter radar simulator is presented, that is able to generate a very accurate synthetic radar signal, by solving the radar equation over a synthetic meteorological environment. Precipitation phenomena are modelled through a population of hydrometeors (rain drops, dry or melting snowflakes) falling through the radar resolution bin. The synthetic radar signal is generated by adding up (in amplitude and phase) all the contributions coming from each single scatterer, present into the virtual radar bin.

As far as the radar sensor is concerned, it is possible to take into account the effect of wave polarisation, antenna and receiver characteristics. The effect of propagation, like differential attenuation and phase shift, can also be introduced in the simulation.

Synthetic signals obtained from the simulator are aventually compared with actual radar measurements, carried out both on averaged (Z, VD, etc.) and pulse-by-pulse basis.