ambiguity resolution to identify true range and velocity. Ambiguity resolution detailed explanation The received signals from multiple PRF are compared to determine true range using the range ambiguity resolution process. Range ambiguity resolution detailed explanation The received signals are also compared using the frequency ambiguity resolution process. Frequency ambiguity resolution detailed explanation Range resolution The range resolution is the minimal range separation between two objects traveling at the same speed before the radar can detect two discrete reflections: In addition to this sampling limit, the duration of the transmitted pulse could mean that returns from two targets will be received simultaneously from different parts of the pulse. Velocity resolution The velocity resolution is the minimal radial velocity difference between two objects traveling at the same range before the radar can detect two discrete reflections: Special consideration Pulse-Doppler radar has special requirements that must be satisfied to achieve acceptable performance. Pulse repetition frequency Pulse-Doppler typically uses medium pulse repetition frequency (PRF) from about 3 kHz to 30 kHz. The range between transmit pulses is 5 km to 50 km. Range and velocity cannot be measured directly using medium PRF, and ambiguity resolution is required to identify true range and speed. Doppler signals are generally above 1 kHz, which is audible, so audio signals from medium-PRF systems can be used for passive target classification. Angular measurement Radar systems require angular measurement. Transponders are not normally associated with pulse-Doppler radar, so sidelobe suppression is required for practical operation. Tracking radar systems use angle error to improve accuracy by producing measurements perpendicular to the radar antenna beam. Angular measurements are averaged over a span of time and combined with radial movement to develop information suitable to predict target position for a short time into the future. The two angle error techniques used with tracking radar are monopulse and conical scan. Monopulse radar Conical scanning Coherency Pulse-Doppler radar requires a coherent oscillator with very little noise. Phase noise reduces sub-clutter visibility performance by producing apparent motion on stationary objects. Cavity magnetron and crossed-field amplifier are not appropriate because noise introduced by these devices interfere with detection performance. The only amplification devices suitable for pulse-Doppler are klystron, traveling wave tube, and solid state devices. Scalloping Pulse-Doppler signal processing introduces a phenomenon called scalloping. The name is associated with a series of holes that are scooped-out of the detection performance. Scalloping for pulse-Doppler radar involves blind velocities