September 2003  Volume 29, Issue 6
ABA Law Pracice Management Magazine, September 2003 Issue
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e-Definitions: From Nuclear Sub to Your Dashboard

with Mark Tamminga

Navigating your way from here to there may soon be a matter of looking at your wristwatch.

Futurists have generally done technology a disservice. Trying to convince us that inane consumer durables like Internet-connected milk-ordering fridges really, really matter has become a mug's game. But there are aspects of the recent tech flowering that do provoke wonder and will make a difference. The Global Positioning System is one of them. Imagine the possibilities of living in a world where the concept of getting lost is a quaint anachronism.

That world is coming at us fast, courtesy of, once again, the military--that most prolific of innovation spinners.

The Russians, you see, based most of their nuclear missiles on land. They knew where their missiles were and where they had to go. The rest was just ballistics. American missiles, on the other hand, tended to be on submarines. They moved. That made the whole job of accurately lobbing warheads from here (which was changing all the time) to there much trickier.

If, however, a Polaris submarine knew exactly where it was immediately before launching the end of the world, well, then we're happily back to simple ballistics again. So in 1964, the Department of Defense commissioned studies that proved the viability of satellite-based location systems. Fourteen years later, the first of the modern GPS satellites was launched. By 1995, the DOD had spent more than $14 billion on the 24 satellites and ground infrastructure that _make up the current GPS. By then, the 1991 Gulf War had proved that the military had a winner on its hands. GPS receivers effectively neutralized the Iraqi home turf advantage of that vast and featureless desert battleground.

Selective Availability
The creation of the system and the level of accuracy attained are true marvels. The two dozen satellites (or more--new satellites are periodically launched to bolster the system) ensure that five to eight satellites are visible from anywhere on Earth. Each satellite carries an exquisitely precise atomic clock. (Oh, and a subsystem designed to detect nuclear explosions. Hey, these things belong to the military; it can load anything it wants on them.) By triangulating against the time signals broadcast by the atomic clocks on each visible satellite, ground receivers can pinpoint location and altitude from anywhere on the globe.

This accuracy was not lost on the civilian world, which began clamoring for access very early on. This clamor took on urgency in 1983 when Korean Airlines Flight 007, relying on faulty onboard navigation systems, strayed 160 miles off course and into Soviet airspace, where it was shot out of the sky, killing all aboard. Out of that tragedy came a directive from President Reagan specifying that military GPS signals would henceforth be freely available to users throughout the world.

Grudgingly, the military complied--but not before messing up the signal a bit for civilians. This Selective Availability, or SA, limited nonmilitary GPS accuracy to within about 100 meters. The military's own Precise Positioning Service was good to 7 to 15 meters.

Through the '90s, sneaky civilians chipped away at this purposeful fudging, rendering it increasingly irrelevant. So much so that on May 1, 2000, President Clinton declared GPS a planetary utility, turned off SA and promised to maintain the system free of charge and unhindered by degradation. The next day, GPS receivers around the world were suddenly 10 times more accurate. Just like that. As one common illustration has it, with SA activated, you really only know if you are on the field or in the stands; with SA disabled, you know which yard marker you're at. The boom was on.

Selective Deniability
The military giveth and the military taketh away. It gave away SA because it had a better idea: selective deniability, or SD. When Clinton sharpened the GPS signal for the world, he also made it clear that GPS could now be denied to targeted areas whenever it seemed worthwhile to blind the other side, like during wartime, for instance. And he wasn't kidding. Civilian GPS units were a lot less accurate throughout Afghanistan for much of October 2001.

If you could build perfectly good rockets and satellites, and didn't much care to rely on the U.S. military's goodwill for what has become a critical tool for getting around on Earth, this whole Selective Deniability thing would not do much to bolster your confidence in the GPS. Indeed, the Russians and Europeans have each been working on their own satellite-based positioning systems. And don't forget the Chinese. They can build fine rockets and satellites, too.

Russia's Glonass system has been operational since 1995. It is slightly less accurate than the GPS, but still close enough for government work. And in 2002, after years of wrangling and in the face of U.S. opposition, Europe committed to launching Galileo, its own positioning system, with a target startup date of 2008. The Chinese are trying to glom onto the European project, but are also rumored to be contemplating a system of their own.

All this action points to one thing: the suddenly critical importance of satellite-based navigation. As GPS receivers (or combined GPS/Galileo/ Glonass receivers) become more accurate and the electronics ever smaller and cheaper, GPS functionality will find its way into phones, PDAs, cameras, watches-basically anything that moves. It won't be long before getting lost will actually take some effort.

Mark Tamminga ( practices law and fiddles with software at Gowling Lafleur Henderson LLP in Toronto. He is the coauthor of The Lawyer's Guide to Extranets (ABA, 2003).