{'fraction_non_alphanumeric': 0.009933774834437087, 'fraction_numerical': 0.008278145695364239, 'mean_word_length': 5.2642487046632125, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Analytical performance comparison of active and passive SMMW imaging for contraband detection

Significant efforts are underway to use either passive or active MMW and Sub-MMW imaging systems to detect objects concealed under clothing. Some have reached the point of commercial availability and have proved useful for contraband detection under controlled conditions. Studies have shown that when the conditions are uncontrolled, passive techniques become less desirable for contraband detection at standoff ranges which give the operators a margin of safety. In recent years, several programs have been funded to investigate using active techniques in the range of 100 to 1000 GHz for standoff detection out to ranges of 100m, a range which has been cited by some to be a desirable operating range. This paper will build on previous work to compare the performance of passive and active sub-MMW imagers used for detecting objects concealed under clothing. The analysis is designed to separate the effects of phenomenology and system components so that tradeoffs in transmitter and receiver characteristics can be performed. The derivation of the analysis and various examples of tradeoffs will be presented.