Wide Open with Gorgon Stare
Written by Peter Buxbaum
GIF 2011 Volume: 9 Issue: 7 (October)
The successful recent deployment of the Gorgon Stare wide-area persistent surveillance system in Afghanistan is providing clear evidence of how advanced electro-optical and infrared (EO/IR) technology is playing an increasingly important role in military ISR.
As military organizations worldwide strive to become more cost-efficient by leveraging the benefits of high-quality ISR and low-light operations, a recent report suggests, they are displaying strong interest in improved EO/IR sensors as potentially decisive force-multipliers. “For this reason electro-optical systems are increasingly being seen as an attractive additional capability enhancer across the full range of military applications,” the Visiongain report said.
In addition, there have been several recent innovations in EO/IR sensor technology that contribute to their growing deployment by military organizations, according to Mike Scholten, vice president for sensors at DRS Technologies. These innovations, which include the ability to generate smaller pixels and to operate at higher temperatures, “enhance the quality and variety of imagery becoming available,” he said.
Developed by Sierra Nevada Corp., Gorgon Stare clusters 12 EO and IR cameras on a General Atomics MQ-9 Reaper unmanned air vehicle to provide wide-area ISR capabilities to the Air Force. It is designed to provide uninterrupted visible and infrared coverage of city-sized areas, giving commander access to real-time motion video.
ITT Corp. was the key developer of the sensors, while Mercury Computer Systems provided the computational capabilities.
Gordon Stare hit one air pocket on the way to Afghanistan, following the leak last year of an Air Force report faulting several aspects of the system. But most of those faults were addressed before deployment, developers say, and fine-tuning of the system continues.
“We have been incrementally improving the system,” said Danny Rajan, director of geospatial information solutions at ITT. “We delivered the final four systems beginning in February. Those are the systems that went into deployment.”
Tactical Imagery
Gorgon Stare provides motion video in three coverage tiers: full field, multiple sub-views of the full field and high resolution “chipouts” of individual views, each of which can be streamed to multiple viewers. These products are provided in real time to tactical and theater forces via the Gorgon Stare ground station/exploitation cell with best-resolution GS chipouts provided directly and in real-time to ROVER users engaged in ground operations.
In addition to these tactical users, the system also provides the same products in near real time to the Distributed Common Ground Systems for exploitation and forensics analysis support. The entire mission data set, which is recorded on board the aircraft, is available post-mission for exploitation and for archiving and discovery.
ITT’s wide-area airborne surveillance (WAAS) EO/IR sensor system consists of five electro-optical and four infrared cameras. “They are capable of digitally capturing an area several miles around, during day and night operations, from 12 different angles, and is compatible with unmanned and manned aerial vehicles,” said Rajan. “What is unique about what we delivered is the ability to view a wide area or view multiple regions of interest within that area.
“What the package does is take a wide field of view, intelligence processing, and the availability of real-time access and combine it all into one system,” Rajan continued. “Other systems can collect wide area data but can’t provide it in real time. Others might have much better resolution than our system but don’t provide wide area viewing. Operational users on the ground can point to specific location such a house or a moving vehicle and have that data streamed to their handheld device in real time. Another user could be in another section of the city and request video on a different target. All this happens simultaneously.”
The same video might be used for real-time tactical purposes and later for a forensic review of incidents. “A ground station operator can have a full field of view of a certain part of a town,” explained Rajan. “If an explosion occurs he can have a unit deployed to that location. Meanwhile, another user can rewind the video to analyze exactly what happened and to collect data on who may have perpetrated the incident.”
In addition to providing the WAAS sensor solutions to Sierra Nevada, ITT has delivered onboard and ground dissemination components such as accelerated compression and standards-based motion image-video formation. These elements are one of many enablers to Gorgon Stare’s tactical networking imagery and video distribution system, which captures, transmits and disseminates large collections of data over small communications links.
ITT approached the sensor development work for Gorgon Stare holistically. “We investigated what users needed and we built components on the basis of that information,” said Rajan. “The Air Force wanted the systems to be fielded quickly. We started with the architecture and worked with SNC and Mercury to ensure real-time access and a wide field of view without sacrificing anyone’s access to data.”
This involved taking data quickly from the cameras and transmitting it to compressors, which enabled the quick storage of data. The imagery, which is compressed and formatted according to commercial standards such as JPEG2000, includes metadata that allows users to quickly identify and find locations of interest. The data architecture includes elements that ITT had previously developed, as well as Mercury’s processing engine, which allows data compression at a high rate of speed.
“The metadata includes key elements of information that allow users to accurately find and point to targets,” said Rajan. “There is no need to send to the ground station computer. The image is accessed directly from the UAV. Using open standards provides users with the flexibility to roam and find what they need.”
Thus far the feedback ITT has been receiving from the field has been encouraging. “Operators are telling us that the imagery looks great,” said Rajan, “and that system is performing significantly above expectations.”
With the Gorgon Stare having been able to overcome its early difficulties, the U.S. military is likely to continue to invest in these types of technologies. “The U.S. has been at the forefront of military electro-optics spending and has pioneered the application of electro-optics systems in new applications,” said the Visiongain report. “Not only does the U.S. account for the largest part of the military electro-optics market, but it utilizes electro-optics systems in the widest range of military applications.”
Encouraging Innovations
Meanwhile, a number of recent innovations in EO and IR sensor technologies are encouraging their use. “The major trends follow the direction of EO technology for digital cameras, more pixels and smaller pixel dimensions,” said Scholten. “High-definition infrared focal plane arrays with ever shrinking pixel size are becoming commonplace.” This IR trend holds for both uncooled and cooled IR technologies, he noted.
“Another significant advancement has been the recent introduction of mid-wavelength infrared detector technology that allows a significant increase in operating temperature while maintaining performance limits,” said Scholten.
In addition, advances in extremely sensitive light detecting avalanche photodiodes represent another significant innovation. “Advances in packaging of the uncooled sensors and the decreasing size of electronics have enabled uncooled camera size to shrink significantly,” said Scholten. “This has also contributed to a decrease in cost. This decrease in size and price is enabling new commercial and military applications.”
DRS has been a leader in many of these innovations. “DRS is widely recognized for discovering and explaining advances in avalanche photodiodes,” said Scholten. “DRS has recently introduced the Tamarisk320, the world’s smallest uncooled infrared camera. This camera is opening up the new markets and applications for uncooled technologies.”
These innovations enhance the quality and variety of imagery becoming available, according to Scholten. The same payload size, weight and power on an unmanned aerial system will now be able to cover a larger field of regard with higher resolution, he explained. “The movement to improved size, weight and power will also extend the time on station of these sensors.” Scholten expects pixel size will continue to shrink. “This will have dramatic impact,” he said. “Very large high-definition formats will now only require a very small chip size, shrinking system size, weight and, ultimately, cost.”
As for the Gorgon Stare, its developers are already at work on an increment two. “ITT is supporting the effort through development of a next-generation, day and night infrared sensor that will provide increased imaging performance to find smaller targets over a larger area,” said Rajan. “This will ultimately enable faster and more accurate image exploitation and decision-making.”
Rajan expects future iterations to include greater levels of on-board preprocessing and compression of imagery. “Users who have a requirement to view a specific place will be able to do so right there and then without having a specific bandwidth allocation,” said Rajan. “These can be delivered to Rovers or other handheld devices.”
The system could also become more intelligent, allowing imagery to be cued or triggered by events. “Having more intelligence on the platform,” said Rajan, “will enable users to notified of people, places and events of potential interest.” ♦
