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In the last half-decade, the extended shortwave infrared (eSWIR) atmospheric band has become a focus of investigation for its potential to provide better object discrimination at range than the visible, as well as the near, shortwave, midwave, and longwave infrared bands, particularly in degraded visual environments such as smoke, dust, and smog. However, any detection band is only as useful as the best available detector, and thus, an investigation into the design of detectors for use in the eSWIR band is necessary before standards are established and applications put into practice. We examine the relationship between detector parameters and targeting performance in the eSWIR band for both passive and active detection. The effects of pixel pitch, dark current, read noise, frame rate, quantum efficiency, and well depth are examined and ranked in importance to an eSWIR system's performance. [ABSTRACT FROM AUTHOR]

There is interest in using body temperature changes in sows as an indicator of the onset of estrus. However, the optimum location to measure body temperature has not been established. The objective of this study was to evaluate the relationships between sow body surface temperature (SBST) measured at various locations and rectal temperature. The study involved 98 multiparous sows weaned in 6 groups between September and November. Sows were housed in individual stalls and were checked daily for standing reflex from day 3 to 7 post-weaning. Temperature measurements were taken daily for 10 days post-weaning [at 06:15 (feeding time), 07:00, 07:30 (heat checking time), 09:00, 11:00, 13:00, 15:00, 17:00, 19:00, 21:00, and 23:00]. Surface temperature was measured using a handheld thermal camera at 4 locations: outer ear, back of the head, vulva, and ham. Rectal temperature was measured using a clinical thermometer. The ambient temperature in the room was measured at the same times as the animal measurements were taken. The PROC CORR procedure of SAS was used to determine correlations between SBST, rectal temperature, and average room temperature at the time of each measurement (RMT). All correlations between SBST at the different measurement locations were strong and positive (P < 0.0001; Table 1) with r values ranging from 0.64 (between vulva and the outer ear) to 0.89 (between vulva and ham). However, correlations between SBST and rectal temperature were relatively weak (range r = 0.14 to 0.18; P < 0.0001). Rectal temperature was not correlated with RMT (r = 0.02; P = 0.12); correlations between RMT and SBST measurements were positive, with the strongest correlations being with the outer ear and the back of the head (r = 0.45 and 0.50, respectively; P < 0.0001). In conclusion, this study suggests strong relationships between body surface temperatures at different locations but relatively weak relationships between these measurements and rectal temperature. In addition, these results suggest room temperature has a greater influence on body surface temperature than on rectal temperature. [ABSTRACT FROM AUTHOR]

Interest in the eSWIR band is growing due to focal plane array technology advancements with mercury cadmium telluride and type-II superlattice materials. As design and fabrication processes improve, eSWIR detector size, weight, and power can now be optimized. For some applications, it is desirable to have a smaller detector size. Reduced solar illumination in the 2 to 2.5 μm spectral range creates a fundamental limit to passive imaging performance in the eSWIR band where the resolution benefit of small detectors cannot out-compete the reduced SNR in photon-starved environments. This research explores the underlying theory using signal-to-noise ratio radiometry and modeled target discrimination performance to assess the optimal detector size for eSWIR dependent upon illumination conditions. Finally, we model continuous-wave laser illumination in the eSWIR band to compare the effect of detector size on active and passive imaging for long-range object discrimination.