GPS Plus GLONASS: Reliable Nav for Tablets

Two new WAAS GPS with GLONASS receivers from Bad Elf and Global Navigation Systems make tablet navigation convenient.

The internal GPS in Apple devices uses so-called Assisted GPS data from cellular towers, but the receiver wasn’t designed for aviation. That’s why it’s not uncommon for an iPad or iPod to struggle with maintaining a GPS signal lock in flight. That makes a remote GPS receiver necessary.

Most Bluetooth GPS receivers are compact enough to toss on top of the glareshield, where it receives the best reception. But it can also become a dangerous projectile in a crash and in turbulence.

Two new satellite receivers, one from Bad Elf and the other from Global Navigation Systems solve that problem.

GLONASS (Global Navigation Satellite System) is the Russian satellite navigation constellation that consists of 24 satellites (the same number as the GPS constellation), providing global coverage to GLONASS receivers.
GLONASS isn’t new to the aviation world. Garmin’s Bluetooth GLO GPS introduced a couple of years ago is a good performer, based on our evaluations. Much of that has to do with it being a dual receiver, using both GLONASS and WAAS GPS. It’s claimed that GLONASS results in 20-second faster lock-on performance, compared to WAAS GPS alone. There’s also better position update rates (up to 10 times per second).

Obviously, a dual receiver is beneficial inside an aircraft cabin. That’s because a receiver mounted down low or obstructed by the instrument panel could lose lock-on.

Bad Elf Lightning
The new Bad Elf GPS for Apple’s Lightning Connector is a redesigned version of the previous 30-pin Dock GPS, a receiver that plugs directly into earlier iOS devices. Elf’s Brett Hack-leman went back to the drawing board when the iPad mini and newer iPhone came along with its miniature Lightning power connector. The only way to make the existing ELF receiver to work was to plug it into the Lightning-to-30-pin adapter. In our trials (Aviation Consumer, April 2013), this proved to be an awkward solution for cockpit use because the receiver hung off the tablet, where it got in the way and was susceptible to breakage.

That problem is solved with the $130 GPS-1008 GPS and GLONASS receiver. It’s made for plugging directly into the Lightning power port and works with the current iPod Touch, iPhone and iPad.

Previous Elf receivers were solid performers, but the new receiver with both GPS and GLONASS step up performance to an even higher level. Thanks to the 99-channel chipset, it’s not uncommon for the receiver to lock on while inside a building without even being close to a window. We used the receiver and an iPhone while biking in the woods and it never lost lock (while a Garmin sports GPS did).

Bad Elf says the receiver has 8-foot accuracy up to 60,000 feet and at speeds up to 1000 mph. During our trials, 12.5-foot accuracy at 5000 feet was the norm. That was in a Cirrus moving along at a more modest 170 MPH. We used the receiver to feed position to the Wing X Pro-7 nav app on the iPad mini that was running iOS7.

Make sure the iPad is charged.
That’s because the Elf Lightning gets its power from the iOS device, rather than using a stored charge. This creates another burden load for the battery-life-challenged iOS-7 operating system. Bad Elf says not to expect any more than 4.5 hours of endurance when plugged into a 4G iPod Touch, under continuous navigation. We experience roughly under 10 hours of endurance with the iPad mini. USB power is passed through the Elf Lightning GPS, so the receiver will charge the iOS device when plugged into a power source.

The receiver fits nicely when connected to the Lightning port. During the two-month trial, it was plugged in all of the time and it easily survived our abuse. In fact, it molds so we’ll against the bottom of the iPad and iPhone 5 that it’s hardly noticeable. The device comes complete with a USB cable for charging and has a detachable keychain lanyard.

German manufacturer Global Navigation Systems previously offered the GNS5870 GPS receiver, a good performer with impressive battery endurance and GPS receiver performance. The follow-on GNS2000—with a 99-channel GPS WAAS and GLONASS receiver—provides equally impressive battery life. While rated for 10 hours of life, the unit exceeded that over several days of navigating and using Bluetooth connectivity.

The GNS2000 is smaller and thinner than a pack of gum and it easily slides in a shirt pocket (we forgot it was there and almost sent it through the wash). It’s also simple to use. It has a single on/off slide switch on the side of the case, next to the Mini-USB socket for attaching the charger. A full charge is achieved within a few hours.

There are three annunciators on the front of the case, including a battery annunciator that blinks red when the device is charging, a Bluetooth annunciator that’s steady blue when connected, or flashing blue when it’s not. There’s also a green GPS status lamp. You know when the receiver is locked on when the lamp is steady green, or acquiring when it flashes, although you won’t see it flash for long.

Signal lock is the fastest we’ve seen from any receiver. The company says that typical cold and warm startup is around 35 seconds, while hot startup is under one second.

The receiver also has a position data logging feature, with a 15-hour internal memory (after which the previous data is overwritten). Using the GNS2000Track application, logged data can be transferred and saved in NMEA or Google Earth (KML) format. The GNS2000 is compatible with Apple iOS and also with Android devices (starting with 2.3 Gingerbread).

We couldn’t find any nits with the GNS2000 except for the cost to ship it from Germany. You could, however, buy it through Sears/ePowerBuys for $155. We also found it on Amazon in that price range.

Editor in Chief Larry Anglisano has been a staple at Aviation Consumer since 1995. An active land, sea and glider pilot, Larry has over 30 years’ experience as an avionics repairman and flight test pilot. He’s the editorial director overseeing sister publications Aviation Safety magazine, IFR magazine and is a regular contributor to KITPLANES magazine with his Avionics Bootcamp column.