UAV Requirements Draw Certified Receivers from Accord/NexNav

October 16, 2013  - By 0 Comments

To fly a UAV in the U.S., you’d better be able to avoid any other aircraft — and ADS-B is one component of that capability. When the FAA and agencies around the world get their UAV regulations aligned with those levied on passenger-carrying aircraft, GNSS receivers on board UAVs will likely need to be qualified to equivalent standards. One company is already there.

When I was wandering around the show floor at the Association of Unmanned Vehicle Systems International (AUVSI) in Washington, D.C., in August, I got a pleasant surprise when I bumped into an old friend I knew from Calgary. Jayanta Ray was a grad student at the University of Calgary (U of C) when I was at NovAtel a few years ago. The students of the GNSS courses at U of C were often at local Calgary ION chapter meetings I organized or attended; there were also a few joint industry-university projects, and there were many, many discussions. So meeting Jayanta (Jay) at the Accord Systems/NexNav booth was a pleasant surprise, and it was good to renew our acquaintance.

This got me thinking that maybe some of that U of C receiver magic had somehow found its way through Jay into the airborne qualified receivers that Accord Technology is offering for UAVs. Jay is actually a member of the GPS World Advisory Board, and provides a great overview of what’s good and what’s different about airborne qualified receivers in this month’s issue of GPS World.

NexNav mini is also qualified for airborne GPS and ADS-B use.

NexNav mini is also qualified for airborne GPS and ADS-B use.

NexNav mini is also qualified for airborne GPS and ADS-B use.

NexNav mini is also qualified for airborne GPS and ADS-B use.

Accord Technology is based in Phoenix, Arizona, and is the U.S. arm of Accord Software and Systems of Bangalore India, specializing in FAA-certified airborne versions of Accord’s GPS receivers.

At AUVSI, one of the hot topics was “Sense and Avoid” — if you are to fly a UAV in the U.S. National Airspace System (NAS), you’d better be able to avoid any other aircraft, and maybe also be able to tell other aircraft in the NAS where you are. ADS-B (Automatic Dependent Surveillance-Broadcast) is one component of that capability. ADS-B uses a network of ground stations that relay ADS-B transmissions from aircraft (called ADS-B Out) in the NAS to the Federal Aviation Administration (FAA) air-traffic management system, and the signal is also available to aircraft flying in the system if they are equipped to listen to the message (ADS-B In). Air Traffic Control (ATC) can then verify that you are where you are supposed to be, and your actual position shows up more readily on their tracking systems. Right now, ATC makes extensive use of radar tracking and aircraft transponder signals to track aircraft — ADS-B will be more efficient, less costly to maintain, and is capable of aircraft-to-aircraft position reporting. By 2020, it will be mandatory if flying within the U.S. NAS.

The other part of this story is that, eventually, when the FAA and other agencies around the world get their UAV certification regulations aligned with those levied on passenger-carrying aircraft, GNSS receivers on board UAVs will likely need to be qualified to equivalent airborne standards.

Accord has already done an enormous amount of work to qualify its NexNav receivers for both requirements, and was at the AUVSI conference to let the UAV community know that these receivers are available now. If you were developing a new UAV now, with a view to selling lots into the anticipated wide range of commercial applications, its certainly going to help your case with the certification authorities to install as much off-the-shelf certified avionics as you can. Accord already sells these receivers to a number of general aviation system manufacturers, and also supplies stand-alone ‘TSO’ed” receivers in enclosures for use on a number of aircraft types. When an airborne receiver is granted the TSO (Technical Standard Order) designation by the FAA, it recognizes that the receiver has been designed, built and qualified to stringent airborne technical requirements and is authorized by FAA for use on aircraft.

So how does a company with its HQ in India get to hold an FAA TSO for a GPS receiver? Well, other than taking years to develop the receiver in accordance with approved development standards, document the hardware and software design, and conduct test and verification activities, the company also proves to the FAA that the receiver meets the FAA-specified airborne GPS functional requirements. Loads of engineering work — and then you have to convince FAA that you did it all and did it right.

Accord in Bangalore actually teamed up with AvValues in Phoenix to form a joint venture known as Accord Technology (AT) to work the project together. Most of the original receiver development work was done in Bangalore, while AT in Phoenix became responsible as the design authority, and for production, certification activities, customer service, product support, and business development. Naturally, Accord in India still does ongoing engineering support and supplies receiver cards to AT under contract. The other twist to the story is that final assembly and test is carried out at the AT facility in Anchorage, Alaska, where the TSO was approved by the local FAA office.

But Accord isn’t only into airborne receivers. The company has been around since 1991 and has significant engineering resources (around 400 electronic and computer engineers) — with more than 700 man-years of GNSS R&D and production involvement. Here are some examples of the other GNSS products which Accord has in its technology/product inventory:

GPS L1 RF down-converter.

GPS L1 RF down-converter.

GPS RF & Baseband.

GPS RF & baseband.

GPS module.

GPS module.

GPS Spacecraft Positioning System (SPS).

GPS Spacecraft Positioning System (SPS).

Time-code generator.

Time-code generator.

SPS was developed for the Indian Space Research Organization (ISRO) and has been flown on all Indian low-Earth-orbit satellites, including IRS P4/5/6, TES, CartoSat, SRE and OceanSat.

IRNSS Reference Receiver.

IRNSS Reference Receiver.

The Reference Receiver is fielded in the ground-monitoring network for the Indian Regional Navigation Satellite System (IRNSS), which may mean that the ground network is using at least dual-redundant reference data, as NovAtel has also provided a similar receiver for IRNSS. Accord is also working on IRNSS user receivers.

Other receivers include high-dynamic GPS-GLONASS receivers, GPS/GLONASS/Gagan SBAS receivers, an internal GPS/GLONASS/Gagan simulator, and a handheld GPS/Gagan receiver with integrated three-axis compass and pressure altitude sensor — the latter used by a number of paramilitary forces.

Accord GNSS roamap.

Accord GNSS roamap.

And as can be seen from the Accord GNSS Roadmap, they aren’t done yet!

You might ask yourself, where in the heck did all this come from? Certainly, there is an element of internal support with work for ISRO and Indian forces, but you don’t jump into this without some background. Well, the principle activity for Accord has been and still remains high-integrity software development for avionics systems — this is probably what Accord is known for in Europe and to a certain extent in North America. Its customer list for RTCA DO-178B/C airborne software sounds like a who’s who of aircraft and helicopter manufacturers — including Airbus, Boeing, Mitsubishi, Gulfstream Eurocopter/AugustaWestland/NHIndustries, Sikorsky, and Hindustan Aeronautics Limited (HAL).

Accord’s activities have included complete and partial life-cycle activities — all the way from requirements definition, software design and development, to independent verification and validation. For those of us who’ve worked in this field, we recognize that these are considerable technical capabilities — indeed, more than 50 engineers at Accord have been trained in the art of airborne software development by FAA-qualified engineering representatives. Working in this area and successfully bringing avionics systems through the qualification/certification process, companies either become capable or break all their bones trying! Clearly, Accord has been schooled in systems that are at the forefront of avionics technology, and has passed through the practical fire of qualifying airborne systems successfully.

So, it’s not really surprising that Accord went on to spin off into airborne GNSS receiver development once it gained wide visibility and knowledge of aviation technology and began to look at related markets. And with the Indian government policy of developing indigenous industries, Accord likely had some internal Indian customers. Quite a number of parallels with the way Europe has encouraged its own GNSS industry through the Galileo program.

With several avionics OEM manufacturers already using embedded NexNav TSO certified receivers in their systems using incorporating licensed designs, Accord looks well positioned to continue its airborne market growth. Accord’s success has so far been in general aviation, but it has wider aspirations, which include commercial transport aircraft (airline aircraft) — this is a segment which has the highest level of development/certification scrutiny and is therefore the most expensive segment in which to compete. Let’s hope Accord continues its growth and there is room in an expanding market for these relative newcomers.

Tony Murfin
GNSS Aerospace

Tony Murfin

About the Author:

Tony Murfin is managing consultant for GNSS Aerospace LLC, Florida. Murfin provides business development consulting services to companies involved in GNSS products and markets, and writes for GPS World as the OEM Professional contributing editor. Previously, Murfin worked for NovAtel Inc. in Calgary, Canada, as vice president of Business Development; for CMC Electronics in Montreal, Canada, as business development manager, product manager, software manger and software engineer; for CAE in Montreal as simulation software engineer; and for BAe in Warton, UK, as senior avionics engineer. Murfin has a B.Sc. from the University of Manchester Institute of Science and Technology in the UK, and is a UK Chartered Engineer (CEng MIET).

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