The history of GPS

The United States Air Force never really wanted GPS.  The 621B program, the precursor to GPS, was underfunded.  After it evolved into the GPS program in the early 1970s, the Air Force largely neglected it, to the point of disowning it and defunding it.  A few times, it tried to kill its own creation, and GPS was kept alive by the Pentagon’s largesse…

One reason the Air Force was slow to embrace GPS is the space-based projects were never seen as a priority.  “The Air Force is not a big user of space,” says Scott Page..”The Air Force gets to build for space, but the Marine Corps, Army, and Navy are much more reliant on actual space services than the  Air Force itself is.  The budget for space is in the Air Force, but in terms of the number of customers and users, they’re all in the other services.

Another source said “…the Air Force is pilots who fly planes.”

That is from Greg Milner’s new and interesting book Pinpoint: How GPS is Changing Technology, Culture, and Our Minds.

Milner also relates how the park rangers in Death Valley National Park have the term “death by GPS.”  It refers to park users who follow their GPS and then die:

It describes what happens when GPS fails you, not by being wrong, exactly, but often by being too right.  It does such a good job of computing the most direct route from Point A to Point B that it takes you down roads which barely exist, or were used at one time and abandoned, or are not suitable for your car, or which require all kinds of local knowledge that would make you aware that making that turn is bad news.



There was a mid-air collision over the jungle in Brazil between an airliner and a smaller plane which was partly attributed to GPS -- normally planes wouldn't accidently collide in the middle of nowhere, but both of them were following GPS along the same path. In the old days, a human navigator would plot the route and there'd be enough slop in the flight path so that wouldn't happen.

Two airliners collided over the Grand Canyon in 1956 long before they had GPS.

Both Mark Thorson and Joan are right. MT about the infamous US vs Brazil collision, where the US pilots were briefly imprisoned, and Joan about the famous case that prompted the need for more thorough air traffic control.

In the Grand Canyon collision, the two planes were flying around the same cloud formation which would have the tendency to bring them together. The Brazil crash was in clear weather.

As a pilot for a large international airline I agree about your comments on GPS. Years ago flying in non-radar coverage over the Atlantic or Pacific
aircraft on the same "Airway" would be as far as a mile or two from the center of the airway as the gyros in thier INS slowing degraded. Now with
most planes having GPS aircraft flying the opposite direction fly directly
over or under us( 1000 feet verticle seperation above or below, a/c flying easterly directions fly odd thousand altitudes and westerly flying aircraft
fly even thousand altitudes).

As far as the Grand Canyon collision, that was due to large amounts of tourist flying aircraft in a relatively small constricted area.

My bad, Joan. I thought you were talking about a more recent accident over the Grand Canyon. However even though the 1956 crash involved to airliners, it does not really pertain to the accuracy of GPS as both aircraft were off the airways avoiding weather.

Yes it's kind of scary as a passenger to see commercial planes approaching one another with 1000 feet vertical separation; I've seen it at night.

If curious, an article stated that on average one person dies per year due to heat and another death is due to other causes in Death Valley National Park..

It's useful (if pedantic) to remember that there are two quite separate technologies here. GPS is a system that allows you to determine your position. Navigation software uses map information plus your position to decide how you should travel to another position. US English often uses "GPS" to refer to the combined system, UK English often uses 'sat-nav', which is in some ways a little more accurate.

Anyhow, it's the mapping and navigation that is the technically hard part nowdays. In some ways that's good, because there are potentially many competing sources of map data and navigation methods. And most places aren't Death Valley, so bad navigation usually just annoys you, rather than trying to kill you.

This. GPS is just a receiver antenna plus a signal decoder that yields coordinates. Inaccurate maps it's another issue. Also, map reading is a skill like reading algebra or computer may be easy and natural with experience but meaningless if you lack the knowledge.

Death by ignorance fits better.

It is amusing to see publishers of printed maps touting that their products feature "GPS coordinates," those thin lines that were previously known as latitude and longitude. Navigation coordinates weren't invented yesterday, and neither were questionable roads and strandings in the desert.

Driving around old mining roads in Nevada with my father, now and then we might high-center the pickup. This was a sign that we had gone far enough, and we would jack up the back, put something under the wheels, and back off. My father never wanted four-wheel drive because he figured that would just allow him to get stuck in a more difficult place that would take more effort to work out of.

The Galileo project in the EU supposedly will have GPS that's accurate to individual lanes in a superhighway (so it's said). I've used GPS to locate Greek farm property boundaries. Greece has no so-called "cladestral" surveys where stuff is accurately measured and recorded, instead, it's local documents that say "from that old olive tree to that boulder" for farmland (which btw due to a low population density and restrictive zoning, is presently largely worthless albeit quite beautiful).

That's essentially how the metes-and-bounds system in the US worked before the creation of the Public Land Survey System to survey lands acquired and traded/sold after the colonial era.

It's a cadastral survey, not a "cladestral" survey. Yes, Greece doesn't have one even though the EU has (apparently) funded several for Greece.

I'm surprised Cowen doesn't mention the on-going political controversy about GPS and LightSquared, the company that owns the license for the neighboring spectrum that it intended to use for a nationwide broadband network. Despite objections from LightSquared's competitors and the military (that LightSquared's devices interfere with GPS), in 2011 the FCC authorized LightSquared to manufacture and sell it's broadband devices. Howls of protest came from Republicans who alleged that it was payback for donations to candidate Obama. In response to the military's concerns, the FCC moved to bar LightSquared's broadband network, an action which is being challenged by LightSquared. Think about it: if broadband can interfere with the military's navigation system (airline pilots also have concerns), how are millions of driverless cars going to operate without creating havoc. As I understand the current technology for driverless cars, GPS is only a small part of the navigation system, which relies more on maps and sensors. But that's been the problem with driverless cars: incorrect or inadequate maps and moving objects (and unmapped stationary objects). Most cars manufactured today have GPS, which can tell someone (law enforcement?) where you've been and how fast you drove to get there and when you went there and how long you stayed. With driverless cars, someone (law enforcement?) will even know where you are going.

Plugging Milner's book seems the primary objective here.

The history of GPS/NAVSTAR is well documented and disagrees with Milner's imagination.

After my father, Roger Easton, was inducted into the National Inventors Hall of Fame, the first head of the GPS Joint Program Office, Brad Parkinson, wrote a letter to Inside GNSS. The editor contacted me and allowed me to reply. Here are the two letters.

Where do you think the history of GPS differs from Milner's account?

The point about the Air Force is that it's not just "pilots who fly planes," but even more specifically fighter planes that achieve air superiority. Ground support is another area where the Air Force does it but the customers are other branches.

At the same time, the USAF doesn't want to have any responsibilities taken away, even ones that it doesn't value as much as the end users.

Witness the zoomies tying themselves in knots over drone pilots.

"Good lord man, we can't have NCOs controlling pilotless planes. They aren't pilots."

a little off subject, but of interest nonetheless:

As pointed out by others, this is not a problem of GPS, but rather the navigation software. There have been instances of idiots starting a track that went right over a peninsula and then actually going aground by blindly following it. Ultimately, safe navigation is up to the computer in your head that should be fed by your eyes looking out the giant "video" screen commonly called the windows.

Now there have been actual GPS assisted groundings such as one ship that left the Caribbean to run aground off I believe Delaware Bay because of a bad antenna connection that slowly lured them off course. Again, looking out the window and verifying is the solution.

The magic GPS box is just another 'trust, but verify' situation.

As a computer guy who learned land and sea navigation, I always have paper map/chart, compass, and pencil off-pavement.

On paved roads, I listen to my smartphone, a happy idiot.

(Backcountry Navigator is a really nice app, but for anything but the most well known/marked trail, a phone has to be seen as luxury, not primary, nav. Take a topo.)

Yup, the implications of this largely overlap a thread from a few weeks ago, where Tyler cited some researcher who claims that GPS (and navigation software) is causing human beings to lose navigational skills.

Which might very well be correct. As individuals, the solution for each of us is pretty easy: don't rely 100% on your GPS. This holds for drivers and hikers. And probably sailors and pilots too, although I don't have firsthand knowledge of those fields.

Difficult being so dependent on tech that wouldn't survive a nuclear war, but then how much will?

Having spent plenty of time using Google Maps to plan trips through the middle of nowhere, I'm pretty sure the problem isn't so much that the GPS is telling people to take a shortcut on BLM Road #4250-389 as it is that people tend to assume that any line displayed on the map must be a well-maintained paved road. The advantage of an old school paper map from AAA it simply doesn't show most of the roads that can get people in trouble.

The major predecessor to GPS was the Naval Research Lab's TImation, not 621B. GPS uses Timation's orbits and ground station configuration. Timation had already incorporated 621B's signal almost three years prior to the Lonely Halls meeting (my Dad started Timation in 1964).

Yeah, not sure what the author is talking about, or if he mentions any of it, or Tyler simply didn't read it.

GPS wasn't an Air Force project or need. It was mainly a...Navy...need. The Navy had several systems prior to GPS which were satellite based and the Navy needed them for its ships and submarines to be able to pinpoint their locations in the oceans, and give them exact positions in order to fire their ballistic missiles.

So what's the point about the US Air Force?

The predecessor of GPS was NAVSAT which had been in use since 1967. It was also available to civilian ships, and even the Soviets used it:

GPS is tied to nuclear strategy and that's the actual controversy.

As AIG notes, the Navy can use GPS to turn their arsenal from second-strike counter-value to first-strike counter-force. That steps on the Air Force's toes.

And more generally, radio-based guidance systems have long been associated with first-strike strategies, because obviously the radio-based system is not going to be there to help with the second strike. You need self-contained inertial or stellar-inertial systems for that sort of thing. Also, it's generally thought to be easier to achieve very high accuracies with outside help than with gyros and accelerometers alone.

Circa 1961, McNamara made the AF the lead service in DOD space projects. What you called NAVSAT is normally named Transit. I discuss pre GPS navigation proposals about 17:00 into my talk at the Explorers Club.

On 4/17/1973, the Assistant Secretary of Defense established what came to be known as the GPS Joint Program Office (it was named GPS in the fall of 1973) and made the AF the lead service. However, I argue in my book, GPS Declassified: From Smart Bombs to Smartphones, that GPS stems mainly from the Navy system Timation.

I was interviewed for Milner's book and he mentions me and kindly recommends my book in the acknowledgments. I haven't seen the final version of his book, but, based on the preliminary version I saw from last summer, it is an excellent addition to GPS literature.

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