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 The Role Of COTS Hyperspectral Sensors On Tactical UAVs Commercial off-the-shelf sensors offer key size, weight, power, and cost benefits for high-volume, low-altitude tactical platforms. By Christopher Van Veen T echnical instruments developed initially for military and defense applications tend to be quite adept at meeting mission objectives but are also very expensive to develop and deploy. While the proverbial "$10,000 toilet seat" often performs no more capably than one purchased off the shelf, the point is well taken and reasonably accepted when it comes to specialized imaging and sensing equipment. Sensing instruments must perform their tasks with utmost precision, so multi-milliondollar price tags have been accepted as the cost of doing business. However, instrument manufacturers are successfully challenging this approach with highperformance hyperspectral sensors designed for lowcost, high-volume program deployments. As the Department of Defense (DoD) moves into an era of constrained budgets and financial sequestration, it has become readily apparent that steep prices — for anything — will be difficult to justify and support. Commercial off-the-shelf (COTS) sensors thus become much more attractive, especially as these readily affordable instruments equal and sometimes exceed the performance of well-known multi-milliondollar systems. While sensors such as Raytheon's ACES-Hy have found a home aboard a few midaltitude aircraft and UAVs for the benefit of key strategic missions, these sensors are not viable in terms of unit cost or SWaP (size, weight, and power) constraints for higher volume, low-altitude tactical platforms. In an era of competing Figure 1: A hyperspectral gimbal by Advanced resources Coherent Technologies is shown with financial Headwall Photonics' Micro-Hyperspec sensor. for multiple programs, 24 Electronic Military & Defense ■ www.vertmarkets.com/electronics low-altitude UAVs — such as L-3's TigerShark and Insitu's ScanEagle and Integrator platforms — can be deployed with high-performance COTS hyperspectral sensors that satisfy mission objectives at much lower per-unit price points. Hyperspectral imaging within the military and defense community exists to serve both strategic (high-altitude) and tactical (low-altitude) missions. The closer to an example the ground you fly, Figure 2: Insitu's Integrator iscarries small, of a small, tactical UAV that the faster the required tactical hyperspectral sensors. frame rate of the sensor must be to process tactical information. As a result, smaller tactical UAVs need hyperspectral sensors with performance comparable to what is found on highaltitude aircraft or UAVs. Sensor Requirements Of Tactical UAVs The mission objectives for tactical hyperspectral platforms are not unlike the detection requirements imposed on higher altitude sensor systems — real-time detection of specific target sets based on the unique spectral signatures of those objects or indicators. Specific targets for realtime detection leave telltale hyperspectral signatures that imaging sensors focused on the visible and near-infrared (VNIR, 380 to 1000 nm) and short-wave infrared (SWIR, 950 to 2500 nm) spectral range can detect, identify, and downlink. Disturbed earth, camouflaged areas, or spectral tags are easily spotted once the hyperspectral sensor is told what to look for based on known spectral libraries. Indeed, one of the advantages of hyperspectral imaging is the ability to discriminate and search for an object matching a particular spectral region of interest. This capability makes the military and defense value of hyperspectral imaging quite justifiable as a standard component of an electro-optical infrared (EOIR) sensor suite. The real-time detection of specific spectral targets and the collection and post-processing of the tactical