RDI is an aircraft target recognition technique, which has not been widely explored, but has potential for contributing to automatic air target recognition. The use of simultaneous range and frequency data has benefits in being able to localise aircraft propulsion systems along the range profile, which is not generally possible with other NCTR techniques. For jet aircraft it can theoretically acquire HRRP and JEM data in a single dwell with the appropriate waveform, but in practice it is not normally achievable due to difficulties in designing a radar with the appropriate characteristics. RDI can measure the signatures of jet and propeller aircraft and helicopters.