Commercial, Military

Sensor Payloads

By By Ed McKenna | August 1, 2011
Send Feedback

There is no shortage of diversity in the unmanned aircraft systems (UAS) market. There are UASs the size of Boeing 737s and handheld systems that weigh less than a pound. Most of the headlines and tax dollars, though, are reserved for the large UASs, including the Predator, Global Hawk and Reaper, which pack potent sensor and weapons payloads. However, increasingly sophisticated sensor payloads using commercially developed technologies are boosting the capability of smaller, tactical vehicles.

The expanded use of smaller payloads will help stoke spending in a flourishing UAS payload market, projected by the Teal Group to surge from $2.6 billion this year to $5.6 billion in 2020 worldwide. A large portion of that growth will be in technology for the larger, more costly UASs, according to David Rockwell, a Teal Group senior analyst.

“As tactical UASs get more sophisticated sensors … there will be more money there,” he said. “There are going to be a lot of new programs,” for these systems, sparking opportunities for smaller companies. “The biggest developments are going to be in Synthetic Aperture Radar (SAR) and Signals Intelligence (SIGINT).” Both are at least being contemplated for small UASs.

“Up until recently, you had to get up into the Predator class to have a long range, high-definition (infrared) system or laser target designation, those are making their way into smaller and smaller gimbals,” said Dave Strong, vice president of marketing at FLIR Systems.

FLIR Systems makes several smaller products: a 9-inch gimbal, available with high-definition TV and a laser designator, a 7-inch product with a laser designator and a 3.5-inch gimbal, weighing 2.75 pounds for small UAVs that includes infrared TV and a laser pointer. All of these gimbals were introduced in the last year and half. “The combination of high-definition and laser designation in the 9-inch class is brand spanking new,” Strong said.

Compared with the payloads on the bigger UAV, the major trade-offs are imaging and laser range. “The technologies are getting better and better, so the trade-off isn’t as severe as it was a few years ago,” said Strong.

“Some of this development is being driven by the commercial marketplace,” Strong said. “FLIR operates in the military and commercial space, so some of this (development) is, in fact, being driven by the commercial side of our business where we are being driven to develop increasingly small camera cores and increasingly high-resolution detectors including high-definition infrared.”

The very challenging development of military qualified high-definition infrared detectors was enabled by key technologies, such as the very dense Field-Programmable Gate Arrays “that give you the ability to put the multiple channels of high-definition video processing into a very small gimbal.”

Commercial Technologies

The commercial market has been and continues to be a critical driver of the development of sensor technologies for used smaller UASs. In the case of electro-optical sensors, for example, the development of products like consumer video camera recording devices “have been a tremendous enabler… to put something extremely light and low cost into a small” package, said Dave Vos, senior director of Rockwell Collins Control Technologies and Unmanned Aircraft Systems.

This effort got a boost in the last decade or so from the convergence of commercial development with microelectronics and microelectromechanical systems (MEMS), Vos said. In the 1990s, for example, “dynamically stabilized lenses and image stabilized video recorders began to show up in handheld video recorders in the consumer market.” These systems had “little MEMS rate gyros sensing (the) motion of your hand holding this video camera and then used this motion to compensate either at the lens or on the imagery.”

“The advent of those little sensors those image processing algorithms the high-performance CPUs to process those algorithms … together with tiny cameras and lenses, the charge-coupled devices (CCD), (and) the focal plane arrays all together … made it feasible to make these (small EO) payloads happen,” Vos said.

Breakthroughs in IR detectors have occurred “in literally the last five or 10 years — and we are not done yet. There is no question that the industry is still on the track of reducing size, weight and power (SWaP) improving performance on all of these devices,” said Vos. “We build a highly integrated sensor flight control system boxes; the smallest one is four ounces and it includes everything you need to fly a small UAV in terms of sensing and processing.”

To build the system, the company leveraged technologies “developed for consumer and automotive markets and then repacked that (and) qualified it at more stringent levels … to use it in the UAV market.”

The sensor technologies are, however, advancing at different paces, often dictated by the economics of the market, Vos said. For example, radars are not advancing at the same performance pace in terms of SWaP as the EO spectrum video. (“Consumers don’t need radars,” Vos said.) However, that might be changing as Frequency Modulated Continuous-Wave radar “is showing up in the luxury autos as collision detection systems, so that is driving those radars SWaP down,” Vos added.

Manufacturers of all categories of UASs are keeping tabs on developments in payloads, and integrating them into their platforms, within the necessary size, weight and power limitations.

“Over the last three years, for example, we have upgraded our infrared camera three times,” starting with a long-wave IR, transitioning to a mid-wave IR in 2009 and then a second generation MWIR in July 2010, said Ryan Hartman, vice president of sales and marketing at Insitu.

Insitu offers a family of UAVs including the ScanEagle; NightEagle; Inceptor, an unmanned helicopter; and the Integrator, which won the U.S. Navy’s Small Tactical Unmanned Aircraft System contract valued at $43.7 million over two years.

The company gets its payloads from Hood Technology, of Hood River, Ore., which integrates into the off-the-shelf payload technologies from vendors including DRS Technologies and FLIR Systems. The MWIR “enables our warfighters to see at night as if they were operating in the day… (and) differentiate between people in an image carrying a tool versus weapon,” he said.

The Integrator is, in fact, designed to allow for payload flexibility with “an integrated multifunction sensor integrated into the nose and an additional payload bay available for any payload or payloads yet to be conceived,” Hartman said.

AAI Unmanned Aircraft Systems said it is also seeing an acceleration of change with regard to the UAS sensor payload technologies. “If you were in the U.S. Army and were going to use an unmanned vehicle to lase a target back in 2002, you needed to use a 1,600-pound Hunter aircraft carrying a several hundred pound payload,” said Steve Reid, senior vice president and general manager, AAI Unmanned Aircraft Systems. “Two years ago we rolled out that capability in a 470-pound Shadow aircraft carrying about a 40-pound payload.

“We know there are payloads in development that will be able to do a similar laser designation mission on a 60-pound aircraft with a 15 or so pound payload … and hope to be able to flight test (them) on our smaller Aersonde later this summer,” Reid said. AAI said it is also planning to flight test SAR payloads on the Shadow UAS this summer on two test aircraft it developed and built with two test aircraft with “two technology partners representing SAR capabilities,” Reid said.

“What we did is expand Shadow to a two bay configuration; the idea is we would still retain our EO/IR capability but also carry (the new technology) on the same mission,” he said. The Shadow currently uses a gimbaled plug-in optical payload (POP) 300 EO/IR sensor from Tamam, a division of Israel Aerospace Industries.

AAI is also exploring possibly adding SIGINT and electronic warfare capability, said Reid. In the case of SIGINT, “there is some funded work underway (with our customer) to take a look at it. I don’t want to set too high expectations there. It is more laboratory feasibility at this stage.”

Size Constraints

As payloads get lighter and more compact, Reid said it is the volume, and not necessarily weight, that has been a bigger challenge. “The Shadow is a pretty compact aircraft,” he said. It was designed to be taken apart and moved on the back of a Humvee.

Insitu’s smaller UAVs face much tighter constraints than the Shadow. The two-bay Integrator is capable of carrying up to 37.5-pound payload compared with the Shadow’s 85-pound limit. However, even with those limitations, Insitu offers a SAR payload option for its ScanEagle. Of course, that option is nanoSAR the world’s smallest SAR from ImSar.

“Our focus is (to add) SWaP and compliment other sensors (on board) with all weather imaging capabilities, so you have high-precision geo-location at day and night and in smoke, fog, dust,” said Ryan Smith, president of Imsar, of Springville, Utah.

“On average, the nanoSAR is an order of magnitude smaller than the other SARs in size, weight, power … and cost,” he said. “It weighs a couple of pounds and uses anywhere from 15 to 30 watts, and we have one that is about 6 by 6 by 6 inches.”

Among industry observers, the viability of using existing SAR and SIGINT technologies on the small UAVs is somewhat controversial. The question is “how to scale them down to smaller and more easily deployed solutions,” said Vos. “There are some fundamentals the wavelength and the sizes of the antennas and transmitters. There is a lot of physics there that has to be worked (out).”

Despite the debate, there is little argument that SAR and SIGINT technologies will eventually be deployed on the smaller systems. In fact, Smith said ImSar is busy building an even smaller SAR, which it expects to roll out later this year.

This could mean the technology may soon be deployed on the handheld UAVs, such as those produced by AeroVironment. The Monrovia, Calif.-based company touts a family of very small UASs ranging from the 15-ounce Wasp with a payload capacity of 3.5 ounces to the 13-pound Puma, which can carry 2.5 pounds. In between is the Raven, which weighs about 4.5 pounds and can carry up to a pound, according to Rick Pedigo, director, small UAS at AeroVironment.

“We have actually produced more than 17,000 air vehicles,” Pedigo said. The Army alone has contracted for more than 2,000 Ravens, he said. The vehicles generally have EO/IR sensor payload that they use on typical ISR missions. However, technology advances are also reaching these micro-level vehicles as the company recently installed on the Puma an EO/IR payload on a gimbal with a laser illuminator built into it, which allows the operators “to separate the flight of the aircraft from what it is (they want) to look at.”

Plans are in the works to upgrade the Raven and Wasp platforms, which still have “fixed camera EO/IR” systems that limit the UAV to using one sensor technology at a time and force operators “to fly the airplane and get it in the position (to) see what (they) want on the ground,” Pedigo said.

“There is a push now to go beyond the usual ISR EO/IR piece,” said Pedigo. Even advanced technologies, such as SAR and SIGINT, have, during the last couple of years, been “catching up to something that fits our SWaP.”

When considering changes, “what we use as our criteria is that we want all of our UAVs regardless the size … to be hand launched. That is our niche market.”

Next month: Test Equipment

Avionics Magazine’s Product Focus is a monthly feature that examines some of the latest trends in different market segments of the avionics industry. It does not represent a comprehensive survey of all companies and products in these markets. Avionics Product Focus Editor Ed McKenna can be contacted at [email protected].


AAI Corp.
Alenia Aeronautica
BAE Systems
Boeing www.
Controp www.
DRS Technologies
Elbit Systems
FLIR Systems
General Atomics
Hood Technology
Israel Aircraft Industries
L-3 Communications
Lockheed Martin
Northrop Grumman
Rockwell Collins
SELEX Galileo

Receive the latest avionics news right to your inbox