A time-integrated range-Doppler map shows the micro-Doppler characteristics of targets in radar images that enable an operator to classify different target types and to classify different activities being done by the targets. A time-integrated range-Doppler map is a compilation of range-Doppler maps over time that results in a spectrogram-like characterization of Doppler while maintaining the range information as well. These are compiled from the range-Doppler maps by taking the maximum value for each pixel over a time range. The time resolution is overlapped onto the range resolution, which is in effect a rotation of the traditional spectrogram which compresses range. This type of radar imaging also allows multiple subjects to be viewed simultaneously and avoids tracking issues in spectrogram creation.