Sensor-based imaging systems generate invaluable information for modern warfare, but a serious challenge exists to the timely use of that information. Data links that provide the transmission backbone from the sensor platform to the ground station lack the necessary bandwidth. Improvements in data communications will not be sufficient to meet the challenge, because the next generation of defense electronics systems will include new sensors. Hyperspectral imaging (HSI) and laser radar (LADAR) will augment, but not replace, the electrooptic infrared (EO/IR) and synthetic aperture radar (SAR) sensors currently used today. As data links increase in bandwidth, they continue to lag behind the breadth and depth of new, sophisticated sensors.
Imaging systems can address the challenge by using computing technology to make better use of existing data-link bandwidth. Processing power co-located on the sensor platform can be used first to turn raw data into images, then for image compression, and, at the most sophisticated level, to execute image exploitation algorithms, such as change detection in the comparison of two images. Each level requires more computing power, but enables the data link to be used more efficiently to transmit useful information.
While more compute power is required on the sensor platforms, another trend is making it difficult to deliver: the sensor platforms are becoming increasingly smaller. Defense forces always need more intelligence-gathering assets and, in recent years, much of this need has been met by placing sensors on unmanned vehicles (UVs) — which are airborne (UAVs), ground-based, or undersea. Early implementations of these UVs, such as the Global Hawk and Predator UAVs, are fairly large platforms, but each succeeding generation is smaller.
Cost is one factor behind a desire to make these unmanned platforms smaller, but so are changes in threats and operations. Next-generation platforms will operate in a more lethal battlefield environment brought about by the worldwide proliferation of advanced detection technology. Using multiple, smaller platforms offers a greater likelihood of system survivability than a single, large platform. More positively, new operational concepts, such as cooperative behavior and swarming, are expanding the potential capabilities of small platforms.
The Need for Powerful, Small, Rugged Computers
For system designers, the resulting challenge is to put more processing power adjacent to sensors inside smaller platforms. They require higher levels of computing power in very small packages that are rugged enough to withstand operation within deployed UVs. While needs vary across a range of implementations, requirements for next-generation embedded computing systems can be summarized as follows:
- Greater Than 100 GFLOPS — Systems can certainly be implemented with less than 100 GFLOPS of processing power, but image-exploitation algorithms, such as change detection, georegistration, or automatic target recognition (ATR), demand that level of processing or more.
- Less Than 10 Pounds — Desired weight and size are, of course, platform dependent. There is a class of smaller UAVs with a total payload capacity ranging from 60 to 200 pounds. In a general sense, it is reasonable to allocate up to 10 pounds of that payload capacity to computing, but not much more.
- Significantly Smaller Than Half-ATR Form Factor — The ATR system for standardized packaging of electronics was created to meet the needs of deployment in manned aircraft. New generations of UVs are not built to fit human dimensions, so it is not surprising that the ATR form factor, even in its half-ATR short form, is simply too big.
- Flexible Enough to Support a Range of I/O Protocols — An embedded computing system that is processing sensor input must be flexible enough to support multiple types of sensors. Sensor payloads can change from one type to another, or use multiple types within one payload. This translates into a need to support multiple I/O protocols, often on a customized basis.
- Able to Withstand Difficult Environmental Conditions — Despite their technical sophistication, defense electronics systems must deliver uncompromised performance under difficult environmental conditions, including excessive heat, humidity, poor air quality, high altitude, shock, and vibration. Embedded computers must be able to keep their electronics from overheating, even when temperatures range up to 55°C and the air is too thin to be used for cooling. At the same time, they must possess the enhanced mechanical integrity to withstand high shock and vibration forces at various frequencies.
A fully integrated ultra-compact embedded computer that can meet the stringent demands of sensor imaging within next-generation unmanned platforms is the ideal solution. The PowerBlock 50 from Mercury Computer Systems is an example of a fully integrated ultra-compact embedded computer. To meet the first requirement — high performance — it features a modular architecture that allows for flexible configurations of multiple processors, delivering over 100 GFLOPS. Processing choices include PowerQUICC III, Xilinx Virtex-4, and Intel processors.
A fully configured system weighs below 10 pounds and measures 4.1 × 5.3 × 5.8" (105 × 134 × 148 mm). It can be held comfortably in one hand. Gigabit Ethernet and RS-232 are two standard I/O protocols supported by the computer. The system's modular architecture facilitates interfaces to multiple application- specific protocols, and the development of customized interfaces for unique I/O formats.
Computers such as this feature a chassis designed to isolate its internal electronics from all external environmental and physical conditions, allowing deployments in harsh environments. Liquid cooling efficiently removes heat at any altitude. Rugged features include o-ring sealing for pressure, humidity, and EMI isolation; high-reliability connectors; extended temperature ranges; and locking modules for shock and vibration immunity.
This article was written by Thomas Roberts, product marketing manager at Mercury Computer Systems, Chelmsford, MA. For more information, click here .