Electronic Military & Defense magazine was developed for engineers, program managers, project managers, and those involved in the design and development of electronic and electro-optic systems for military, defense, and aerospace applications.
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Technology Electronic Military & Defense Annual Resource, 5th Edition 11 type), the machine-learning community provides algorithms to select the best subset of Mueller matrix elements that can be used meet the probability of detection (PD) and probability of false alarm (PF) constraints. Once this subset is selected, an instrument can be designed that measures only the subset, which reduces instrument complexity and increases bandwidth (in whatever modulation domain is used). The caveat is that, in order to find an optimal subset, a fully measured training dataset is required. Once an instrument design is chosen, then data collection and training for classification can occur. Goudail's group has shown that the optimal contrast between two distributions of Mueller matrices can be computed x , and we have done work in the multiclass TTI problem. Drawing from the imag- ing science and machine-learning communities has allowed for classification of Mueller matrix data of multiple targets and backgrounds, and the application of these techniques is straightforward. However, the lack of a robust Mueller matrix dataset with which to train remains, and no group at the moment has alleviated this issue. Our scatterometer likely will be operational in two to three years, allowing our group time to assemble a more robust training dataset. Finally, computing power has grown to meet the level of processing required to deploy real-time active polarim- eters. Recent advances in inexpensive computational power, afforded by gaming hardware graphics processing units and multicore CPUs, along with fast memory buses to transfer the data between the camera and various processing units, have facilitated both fast algorithms and data transfer from camera hardware to processing hardware. Current computing power makes it possible to process the amount of data required to accomplish TTI using active polarimetric instruments at around 15 to 30 fps, all in a relatively portable and inexpen- sive processing package. HyDMIP-P Our group has designed and built an active por- table Mueller matrix polarimeter, the Hybrid Domain Modulated Imaging Polarimeter-Portable (HyDMIP-P). This active imaging polarimeter consists of a typical, rotat- ing retarder-style (temporally modulated) active illumina- tion source and a spatio-temporally modulated imaging receiver. A schematic is shown in Figure 7 on page 12. The receiver consists of two rotating retarders (temporal modulation) and a micropolarizer array (spatial modula- tion). The receiver by itself constitutes a full spatio-tem- porally modulated Stokes (passive) polarimeter. The HyDMIP-P was designed using linear systems theory, and we realized a tradeoff of spatial resolution for temporal bandwidth. We used four rotating retarders in total, which SINCE 1968 508-695-0203 mini-systemsinc.com info@mini-systemsinc.com 20 David Road, North Attleboro MA 02761-0069 Thick & Thin Film Resistor Products • Faithful scheduled deliveries under 2 weeks • Values from 0.1 Ohm to 100G Ohm • Abs. tolerance to ±0.005%, matching to ±0.0025% • TCR's to ±2ppm/°C, tracking to ±1ppm/°C • Operating frequencies to 40GHz • High performance at cryogenic temperatures • Case sizes to 0101 • Space level QPL's, F.R.-"S", per MIL-PRF-55342 • Zero failures with over 200 million life test hours • ISO 9001:2000 certified • Full line of RoHS compliant products • 24-hour quote turnaround 47 YEARS OF EXCELLENCE PROVEN RELIABILITY. TRUSTED PERFORMANCE. PRECISION PASSIVE COMPONENTS & ELECTRONIC PACKAGES Electronic Package Products • Hi Reliability Hermetic Packages: • Lightweight glass sidewall flatpacks • Metal flatpacks, leadless chip carriers (LCC) and ceramic quad flatpacks (CQFP) • Surface mount and plug-in packages • Hermeticity per MIL-STD-883, Method 1014, Condition A4 (greater than 10 -9 atm cc/sec) • Plating per MIL-DTL-45204 and QQ-N-290 for standard packages (unless otherwise specified) • Custom design available • RoHS and DFARS compliant