Detection range, of course, increases with the ratio of the signal energy to the energy of the background noise and clutter. By employing a high duty factor, high PRF waveform, therefore, long detection ranges can be obtained against nose-aspect targets even in a clutter environment. However, where strong sidelobe clutter is encountered, detection ranges against low-closing-rate (tail-aspect) targets may be impaired because of range ambiguities. In this chapter, we will consider a high duty factor, high PRF waveform, see what must be done to separate targets from ground return, and learn how the signal processing is done. We'll then take up the problem of range measurement, eclipsing loss, and the steps which may be taken to improve performance against low-closing-rate targets.