08 December 2017

Amateur Radio and GPS - We Need A Better Mash-Up

Radio is my hobby. My daytime job has me working with GPS-based high precision navigation and positioning systems at a very busy commercial airport. It is fascinating work and it often exposes me to leading edge of GPS-based developments. GPS and the entire global navigation satellite system (GNSS*) infrastructure has fundamentally changed the way we think about location and navigation, and is directly responsible for saving hundreds of lives. Not just since the systems were introduced, but every single year.

GPS receiver technology gets smaller, cheaper, more accurate and more robust every year. GPS technology is becoming ubiquitous and is already embedded in a huge variety of systems, many the consumer isn't even aware of. I often joke that in the not-too-distant future we'll have GPS-enabled toasters, and I'm only half joking. GPS receivers are everywhere - in your smartphones and tablets, in your car, in airplanes and ships, on the periscopes of submarines, in emergency responder trackers, on the collars of grizzly bears, in self-driving cars, on cellphone towers, on the ankles of criminals released on parole and on the backs of individual Soldiers so they can be tracked on the battlefield.

More and more, GPS receivers are making their way into Amateur radio handheld transceivers, but the integration is only half baked. GPS receivers are making their way into these radios merely as an adjunct to digital modes of operation. Radios like the Icom ID-51Plus, the Kenwood TH-D72 & 74 and the Yaesu FT2DR all have built-in GPS receivers to support either D-STAR, APRS or System Fusion. These modes leverage GPS to provide position information as part of the digital signal. And little else. Of course you can access the GPS status screen as part of the overall radio feature set, and most radios have rudimentary waypoint logging and navigation, but it is all little advanced beyond what a basic Garmin or Magellan unit offered 20 years ago.

Continuing with this 'stuck in the 90's' theme, the transceivers I've used (the ID-51 and both of the Kenwoods) have very limited offerings for both map datums and coordinate systems. For datums many offer just two options - the Tokyo Datum and WGS84. The Tokyo datum offering reflects the country of origin. WGS84 is a world-wide datum, and the 'native' datum of the GPS system. WGS84 is a pretty good datum and works equally well (or equally poorly, depending on your perspective) just about anywhere across the globe. But the lack of coordinate system options is what really stops these transceivers from serving as general purpose GPS units. A coordinate system is built on top of the datum and is what provides the x, y positional values (lat/long, easting/northing, etc.).

Many Amateur radio operators get into the hobby because the emergency response aspect captures their interest. They offer their communications training, expertise and equipment free of charge when disaster strikes. Many are put out on remote sites or made part of mobile response teams and asked to provide regular updates that include a location component.

Other radio Amateurs simply enjoy the outdoors and see Amateur radio as an ideal adjunct to their hiking and backpacking activities. Again, there is a location component to this activity and most outdoors men and women carry a GPS receiver as part of their back country kit.

In both of these instances the GPS-enabled handheld transceiver could fill the bill as a general purpose GPS unit, but the GPS interfaces in these radios work against the user. In each of these radios the only two coordinate systems provided are latitude/longitude and the Maidenhead grid. Great for Amateur radio, but lousy for general location identification. First, nobody but Amateur radio operators use the Maidenhead grid. It's great for identifying your location to other hams, but that's about all. Second, passing latitude and longitude coordinates by voice communications is difficult and easy to mess up. There are multiple latitude and longitude formats - degrees/minutes/seconds, degrees/decimal minutes, decimal degrees - and various callouts for longitude (+/- or east/west) and latitude (+/- or north/south). It is very easy to get confused and mis-call a number.

Three modern (and high end) Amateur radio HTs. From left to right, the Icom ID-51Plus, the Kenwood TH-D72
and the Kenwood TH-D74. All three are extremely capable radios  with built-in GPS. All three make lousy general
purpose GPS receivers. Note the difference in the lat/long coordinate system readouts between the the ID-51
and the TH-D74 and the TH-D72. Which one is right? Which one is wrong? Here's the issue - all are right
The ID-51 and the TH-D74 are presenting the lat/long in degrees/decimal minutes. The TH-D72 in the middle
is presenting the coordinate values in degrees, minutes, seconds

The US Army and NATO recognized this problem in the late 1940's and came up with the world-wide Military Grid Reference System (MGRS). It simplifies location identification by providing a unique set of grid zone identifiers and coordinates for every location on earth, down to a single square meter. MGRS has been continuously updated and is now based on the WGS84 datum to improve world-wide accuracy. Over 20 years ago GPS receiver manufacturers figured out how to program MGRS capability into their products, and virtually every receiver made since 2000 has included MGRS as a coordinate system option.

In 1999 I bought a Magellan GPS 315. This 18+ year-old GPS receiver
had a better feature set than you find in current production Amateur
radio handhelds with built-in GPS, including the ability to display locations
using MGRS (USNG). Integrating many of the Magellan's basic functions into
an Amateur radio transceiver, with its improved GPS receiver technology and
better processors, should be an easy task

I understand the political sensitivity of putting a coordinate system titled 'military grid reference system' in a civilian ham radio, particularly one that is marketed around the world. But the US is the single biggest market for Amateur radios and the manufacturers already build market-specific units that match the local or regional band plans. It should be an easy decision for the manufacturers to include a US-specific coordinate system readout for units sold in North America.

But we can make it even easier for them to decide. In the United States our emergency response, search and rescue and other public services have adopted a variation of MGRS called the US National Grid. The US National Grid (USNG) is simply a version of the MGRS system that is based on the North American Datum of 1983. Its use has been mandated across local, state and federal response agencies. For at least the last five years all standard topo maps produced by the US Geological Survey have a USNG overprint. Most GPS receivers marketed in the US have USNG as a coordinate system option, and a wide variety of smartphone navigation apps provide USNG readouts. The code for translating latitude/longitude into USNG is open source and there are plenty of developers in the market with deep experience integrating USNG readouts into various applications. It should be a 'no-brainer' for Icom, Yaesu and Kenwood to bring on some programming expertise, clean up their GPS functionality and provide a better general GPS interface option.

An example of a USNG readout provided by a simple
smartphone app (USNGApp by SharedGeo).
There is no reason Amateur radio manufacturers can't
incorporate USNG as an available coordinate system
option. It greatly reduces confusion when passing
location information via voice, and first
responders are trained in its use

What should this improved GPS interface provide? Let's start with simple one touch (or button push) access to a GPS window that provides:
  • A large, clear and easy to read main display showing current location in a user selectable format (USNG, lat/long, UTM, Maidenhead, etc.)
  • A sub-display showing location in a second user selectable format
  • The current frequency or repeater ID the transciever is tuned to
From this top page, quick navigation to sub-pages showing waypoint listings, distance and direction to selected waypoints, an easy to use waypoint management screen, and a GPS/GNSS satellite status screen. This is dead easy to achieve with the GPS receivers and CPUs in current radios. The biggest restriction today is screen size and resolution. 

When keying to transmit from the top GPS menu page the primary location ID (USNG, lat/long, etc.) remains in the display so the operator can quickly and easily read off his/her location information to the other station.

Yes, I know that D-STAR, System Fusion and APRS can pass location information, it's a core part of their functionality. The problem is, each of these systems has heavy infrastructure dependencies unless you are working digital simplex. D-Star and System Fusion require you to be hitting a system compatible repeater, and APRS requires you to be able to hit a digipeater. What about simplex? It's doable - all these modes support some level of digital simplex operations. However, few hams practice working voice simplex over VHF & UHF frequencies. Expecting them to be able to configure their radio for digital simplex under stressful circumstances is too much of a stretch.

My argument calls for a GPS interfaces to be embedded in digital and non-digital radios. In this day and age why should GPS technology be restricted to just digital mode applications? It's time to marry up analog Amateur radio with GPS. The use case is well established and the technology is mature and easy to implement. It just makes sense.

So come on Icom, Kenwood and Yaesu - give us a robust, waterproof and shock-proof dual receive analog handheld with a properly integrated GPS capability. When you do I'll be standing at HRO with cash in-hand, and I'm pretty sure I won't be the only one.

W8BYH out

(*Definition time - the term Global Positioning System or GPS refers to the American system of navigation satellites and supporting infrastructure. The accepted term for all satellite navigation systems - GPS, the Russian GLONASS system, the EU's Galileo system, the Chinese Beidou system and others are collectively referred to as the Global Navigation Satellite System, or GNSS)

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