High resolution short range radar

A radar receiver comprising:

• A. a sampler, which samples a received pulse radar signal in response to a control signal, the received signal including short duration radio frequency (RF) pulses of duration .tau. at an actual pulse repetition frequency of PRF.sub.o, and the sampler generating a sampled signal;
• and
• B. a timing circuit, which generates the control signal such that it causes the sampler to take at least one sample of the received signal during each period of duration (1/PRF.sub.o using a sample window of duration .delta., where .delta. is less than .tau.,
• whereby the sampled signal generated by the sampler includes time-expanded replicas of the pulses in the received signal, the time-expanded replica pulses having a normal pulse repetition frequency of PRF.sub.n, which is less than the actual pulse repetition frequency PRF.sub.o.

A radar system for use in training radar operators in a classroom setting using model target, the radar having a spatial resolution on the order of a centimeter, comprising:

• A. a transmitter that periodically transmits sub-nanosecond duration radio-frequency (RF) pulses having a bandwidth in excess of one gigahertz (GHz), at an actual pulse repetition frequency of PRF.sub.o ;
• B. a radio frequency receiver that receives the sub-nanosecond RF pulses reflected by a particular target as periodic pulses in a received RF signal;
• C. means for demodulating the RF signal to produce a baseband signal;
• and
• D. a pre-processor that receives the baseband signal, the pre-processor comprising:
• i. a sampler that repetitively samples the baseband signal in such a way that progressively later samples represent progressively later portions of successive pulses reflected from the particular target;
• and
• ii. means for storing the value of samples in the time period between successive samples, so that when the particular target is within the range of the radar, the signal pre-processor generates an output signal which is a time-expanded replica of the fine shape of the RF pulses reflect by the particular target.