The role of modelling in system design and acceptance

Making accurate predictions of the performance of a complex system such as an airborne radar in a complex environment is notoriously difficult, and for this reason most radar systems continue to rely exclusively on trials for acceptance. Whilst trials have the benefit of demonstrating qualitative performance against the real world, obtaining detailed quantitative measures, for example to compare against a performance specification, is open to much debate. Given that neither modelling nor trials on their own will provide answers to all of the questions an end-user would like to ask, there is clear benefit for both radar designer and end-user in using a carefully controlled combination of trials and modelling. This paper describes some of the radar models and simulations in use or under development within Racal Radar Defence Systems, and discusses the way in which results from these models can be used to mutual advantage during the development and acceptance phases of a typical airborne maritime reconnaissance radar