>>5303566

The need for through-the-wall surveillance sensors has existed for many years. Recent advances in microwave and millimeter-wave (MMW) technologies provide new applications for law enforcement use. These applications include the potential to conduct surveillance through walls and the ability to detect the presence of living persons behind doors or other barriers. Covert surveillance and personnel detection are of high interest to both the Department of Defense in support of Small Unit Operations and the Justice Department for civilian law enforcement applications. Microwave sensors are under development that can detect the presence of persons (and even weapons) behind walls and track moving persons behind walls. MMW sensors are under development which can provide pseudo-images of persons behind the walls including radiometric sensors at 95 GHz, active 95 GHz real aperture radars, and heartbeat detection radars. Radiometric sensors include 2D FPA systems, 1D FPA, scanned systems, and single element scanned sensors. Active FPA radars include illuminated radiometric systems and coherent radar systems. Real aperture MMW radar systems include raster scanned and non-scanned (hand-held) sensors.

>>5303984

Using continuous wave, 94-GHz millimeter-wave interferometry, a signal representing chest wall motion can be obtained that contains both the heart rate and respiration patterns of a human subject. These components have to be separated from each other in the received signal. Our method was to use the quadrature and in-phase components of the signal, after removing the mean of each, to find the phase, unwrap it, and convert it to a displacement measurement. Using this, the power spectrum was examined for peaks, which corresponded to the heart rate and respiration rate. The displacement waveform of the chest was also analyzed for discrete heartbeats using a novel wavelet decomposition technique.

>>5304038

ABSTRACT Electromagnetic fields at millimeter wave lengths are being developed for commercial and military use at power levels that can cause temperature increases in the skin. Previous work suggests that sustained exposure to millimeter waves causes greater heating of skin, leading to faster induction of circulatory failure than exposure to environmental heat (EH). We tested this hypothesis in three separate experiments by comparing temperature changes in skin, subcutis, and colon, and the time to reach circulatory collapse (mean arterial blood pressure, 20 mmHg) in male Sprague-Dawley rats exposed to the following conditions that produced similar rates of body core heating within each experiment: (1) EH at 42°C, 35 GHz at 75 mW/cm2, or 94 GHz at 75 mW/cm2 under ketamine and xylazine anesthesia; (2) EH at 43°C, 35 GHz at 90 mW/cm2, or 94 GHz at 90 mW/cm2 under ketamine and xylazine anesthesia; and (3) EH at 42°C, 35 GHz at 90 mW/cm2, or 94 GHz at 75 mW/cm2 under isoflurane anesthesia. In all three experiments, the rate and amount of temperature increase at the subcutis and skin surface differed significantly in the rank order of 94 GHz more than 35 GHz more than EH. The time to reach circulatory collapse was significantly less only for rats exposed to 94 GHz at 90 mW/cm2, the group with the greatest rate of skin and subcutis heating of all groups in this study, compared with both the 35 GHz at 90 mW/cm2 and the EH at 43°C groups. These data indicate that body core heating is the major determinant of induction of hemodynamic collapse, and the influence of heating of the skin and subcutis becomes significant only when a certain threshold rate of heating of these tissues is exceeded.

>>5303685

5g?

>>5304214

Great, 5G comments?