Better avionics, thanks to cellphones?
It’s certainly a comforting feeling, watching the avionics techs remove old black boxes from your airplane and replace them with the latest units on the market. You’ll now enjoy much better performance, vastly improved reliability, great warranty support and the latest technology that money can buy–but not for long.
The pace of electronics technology isn’t just moving rapidly ahead; it’s zooming. That is possibly why manufacturers no longer brag that the products they are introducing into the market are “state of the art.” These days, almost anything electronic that’s in production is actually “state of yesterday’s art,” a fact underscored by a personal computer company official, who acknowledged that even before the newest machines have entered full production, engineers are adding even newer technology to their planned replacements.
Of course, avionics units aren’t PCs, and buyers don’t plan to trade them in for newer units every year or so. Avionics, and aircraft systems in general, are built to much higher technical specifications, much more demanding performance and reliability standards, severe environmental capabilities and all the rest.
Nevertheless, it’s educational to see what’s happening in the fastest growing electronics market in the world today– cellphones–and its potential future impact on avionics. Here, competition is much more intense than in the PC market, since there is demand for hundreds of millions of units.
At the Institute of Navigation’s annual GNSS Conference in Savannah, Ga., AIN was introduced to what is–so far, at least–the world’s smallest GPS receiver-on-a-chip, built to be incorporated into cellphones. According to its manufacturer, u-Blox of Switzerland, it has 50 dedicated channels (most avionics units have 12 or 24) to track 50 separate satellites simultaneously. Too many? Today, with just single-frequency GPS satellites, yes. But with Russia’s Glonass and Europe’s Galileo coming closer, followed by Chinese, Japanese and Indian satnav constellations, and with dual L1/L5 GPS frequencies also ahead, 50 channels could come in handy.
And then there are things called correlators in satnav receivers. These are the first line of defense in each receiver channel, continually testing the incoming signals to ensure they are from the correct satellite, are undistorted and are in the optimum tracking configuration before passing them to the receiver.
GPS receiver engineers are guarded when talking of their current correlator numbers, but it appears that today’s high-end units could have as many as 10 or more per channel. The tiny u-Blox chip contains one million correlators, or 200 per channel, which–industry experts suggest–could be the reason for its one-second acquisition time to full operation. All you need, the company states, is to add power and an antenna.
For the antenna, you could contact Pulse Engineering of San Diego, which is also chasing the cellphone market with what it claims to be–so far–the smallest GPS antenna in the world. Hardly bigger than a grain of rice, this unit also has remarkable performance specifications.
Should you buy a u-Blox chip and a Pulse Engineering antenna to build a do-it-yourself GPS? They’re inexpensive enough: u-Blox declined to comment, but AIN understands that cellphone manufacturers are looking for GPS receivers in the $5 to $6 range. Pulse Engineering simply says 44 cents each for its antennas. Alas, there’s one catch. Both companies sell their products only in large quantities, starting at 100,000.
For those who would prefer an IRS/GPS unit, NovAtel of Calgary, Alberta has one, and it’s built for rugged geophysical work, including aerial surveying. The six-inch cube, which weighs five pounds, offers high-precision outputs far exceeding those required for ordinary navigation. Unfortunately, it’s not built to a TSO specification, so it wouldn’t be a legal navaid in a corporate aircraft. But its one-off price of around $25,000 is certainly attractive.
Yet these three devices show just how fast navigation electronics technology is zooming ahead, and what we can expect to see in our avionics units in several years’ time. Of course, we’ll have to look closely to see some of them.