Modeling passive millimeter wave imaging sensor performance for discriminating small watercraft

Abstract

Passive millimeter wave (pmmW) imagers are quickly becoming practical sensor candidates for military and nonmilitary tasks. Our focus was to adapt the Night Vision [U.S. Army Research Development and Engineering Command, Communications and Electronics Research Development and Engineering Center, Night Vision and Electronics Sensors Directorate (NVESD)] passive thermal infrared imager performance models and apply them to pmmW imaging systems for prediction of field performance for the task of small watercraft and boat identification. The Night Vision Lab's infrared sensor model has been evolving since the 1950s, with the most current model being NVThermIP [Night Vision Thermal and Image Processing (NVThermIP) Model Users Manual, Rev. 9 (U.S. Army RDECON, CERDEC, NVESD, 2006)]. It has wide recognition as an engineering tool for sensor evaluation. This effort included collecting pmmW signatures for a representative set of targets, conducting an observer perception experiment, and deriving the task difficulty criteria that can be used in NVThermIP for identification of boats. The task difficulty criteria are used by designers and managers to create systems capable of meeting specific performance criteria in the field.

Q-Band Millimeter Wave Imaging in the Far-Field Enabled by Optical Upconversion Methodology

“…As stated previously in Section 2 and referenced in [11] and [12], the images presented were part of a series of tests that were conducted to determine small watercraft identification using current state-of-the-art mmW imaging systems. All images presented were collected in the horizontal polarization only.…”

“…The detector could be used in the scanner without a LNA, but the integration times would need to be very high, and would require significant scan times to reach the performance levels of a detector with a LNA. It should be noted that LNAs are commonplace and used in the scanners presented in [11][12][13], and [14].…”

“…For further comparison, as referenced in [11] and [12], a series of tests were conducted to determine small watercraft identification using current state-of-the-art mmW imaging systems. In addition to our results presented herein, two other scanners were used in these tests.…”

“…However, the drawback to this radiometer is that the RF components are very complex and signal losses tend to increase on the front-end, where a parallel receiver approach is needed to reduce these losses. While both the upconverted imager and the direct detector created more pixels on target and were faster at scanning at the small watercraft identification tests, the downconverter had a higher probability of detection post-data collection and lower noise equivalent temperature difference (NETD) [11,12].…”

Effects of Reverse Radiation Noise on Millimeter-Wave Radiometric Imaging at Short Range

“…When compared with active imaging, MMW radiometric imaging does not radiate any form of radiation, and it offers the advantages of imaging covertly, eliminating specular effects and avoidance of interference with other systems [2]. Additionally, due to the superior capability of imaging through natural and manmade obscurants, MMW radiometric imaging has attracted increasing attention in broad areas ranging from precise guidance to concealed contraband detection [3][4][5][6][7].…”