GPS history

[SeilerBird]

I am an early adapter. I have to get most new and exciting technologies as soon as it is affordable. I had a computer in 1980 and used it mainly for video games. My favorite game was the Microsoft Flight Simulator. I spent many happy hours flying my Cessna 182 all over the country. In 1999 Microsoft released a significant upgrade and renamed it FS2000 and it included a GPS. I had first heard of GPS during the Gulf War when the smart bombs were hitting the tiniest target imaginable. So when I took off and hit the road full time in 2003 I bought a Magellan GPS and it was a total bummer because it was obvious that the GPS had many possibilities but they were very slow. It was obvious it was not ready for prime time at that time at that price point, the cheapest one available.

But it really piqued my interest and I attempted to learn how they work by reading about it online. I was able to get a general understanding of how they worked but a lot has been a mystery to me until tonight. Amazon Prime has a new video called "The Lonely Halls Meeting". The video is superb and will explain everything about how it operates and I could even understand most of it.

https://www.amazon.com/Lonely-Halls-Meeting-GPS-Documentary/dp/B07J2T5624/ref=sr_1_1?ie=UTF8&qid=1541634271&sr=8-1&keywords=lonely+halls

Most amazing is the fact that the GPS chip is now very small and costs $1.50 to add one to your phone.

 

[jymbee]

Amazon Prime has a new video called "The Lonely Halls Meeting". The video is superb and will explain everything about how it operates and I could even understand most of it.

https://www.amazon.com/Lonely-Halls-Meeting-GPS-Documentary/dp/B07J2T5624/ref=sr_1_1?ie=UTF8&qid=1541634271&sr=8-1&keywords=lonely+halls

Most amazing is the fact that the GPS chip is now very small and costs $1.50 to add one to your phone.

Amazing indeed-- thanks for posting. Will definitely watch.

It's incredible the technology available today to your average consumer. "Kids today" in the US who have never know life without the Internet, GPS, streaming video etc. etc. while many of us old timers remember things like party phone lines, just a couple of TV stations that went off the air with the National Anthem around midnight, etc. etc.

I can remember thinking whenever I got lost back then-- gee, if only I had a device that could communicate with an array of geosynchronous satellites in orbit 22,000 miles over the earth...  Yeah, right.   

 

[Larry N.]

I got my first GPS in July 1993 at the big EAA airshow at Oshkosh, a Trimble, it was for aviation only, and it was far from a moving map display. It was three or four lines of text on the display, but it did have a good database of airports and navaids. It was a real luxury on our way home to not have to navigate by "dead reckoning" to go straight to our fuel stop, then straight home.

The Trimble model 19075 came in a nice leather pouch, ran on 4 AAs, and even had a plug in external antenna to run to the top of the panel or windshield area for better reception. I've still got it and it still works. Here's a picture of one on Ebay.

 

[SeilerBird]

That is several generations before my first one. How cool Larry. )

 

[Gary RV_Wizard]

We were working on GPS uses back in the md-80's when I was part of IBM's automotive computing systems operation. We had a major collaborative effort with GM at the time and together were trying to work out how to use cellular phones, computers and GPS in cars, both as an assist for the driver and to assist in vehicle diagnosis and repair. One of our PhD engineers actually invented (and patented)  the first standard data protocol for cell phones and coupled that with a GPS chip set so vehicle location could be reported.  Amazing stuff at the time.  We modified a 1985 Buick Riviera  with a PC built in where the glove box usually resides and it had GPS locator (not navigation) and cellular communications.  I also had a custom-modified IBM Thinkpad that had an attached cell phone and could get on the internet most anywhere (albeit at horribly low speeds).  People would gather around to watch and ask questions if I took it out in an airport while waiting to board.  I was a celebrity among the traveling business man crowd!  ;D

We ended up putting the GPS and PC-in-a-car on the back burner cause the technology simply was wasn't mature enough in 1985 for mass market use, but some smaller companies ran with it for specialized applications.  UPS was one of the first to use onboard computing and mobile data.  Law enforcement was another leading area for mobile computing, GPS and cellular data.  It would be 10 years before enough of the pieces matured to make consumer-grade products practical.

 

[Bobtop46]

I have worked and taught  GPS.  Easiest way that I explained it is nothing more then a big time, speed and distance problem we all learned in school.  In this case the time it takes the signal to go from the satellite to your receiver (in nanoseconds) times the speed of light = distance from the satellite.  With just one satellite this creates a globe with the satellite in the center and you somewhere on that globe.  You could be an equal distance in space from the satellite away from the earth, now do the same calculations for 3 more satellites and the 4 globes intersect in one location.  Your receiver needs to know where the satellites are of course.  You only need 3 satellites for lat/long and 4 for elevation.  1 nanosecond of error in the system = 6 ft on the ground.  The advertised accuracy of the system is a 10 meter globe, or circle on the face of the earth.  Accuracy can be improved for your automotive unit going down the road by assuming that you are on the face of the earth and pair the receiver with accurate maps of the earth like google maps.

Most commercial GPS receivers don't actively track 4 satellites at one time, one or two channels, time share tracking the satellites very quickly. 

An example of current use and how to improve accuracy.  Road and in some cases building construction.  Look at the bull dozier and see the GPS receiver  mounted high on the blade.  What they do is survey a nearby spot down to the centimeter.  Then put a GPS receiver there with a transmitter.  That receiver gets the signal which has a 10 meter circle of error, but you surveyed it and  know exactly where it is, and transmit this error to the bull dozier working nearby removing the error from its receiver.  Now the bull dozier can put the road within a centimeter of where it is suppose to go.  This can be done on a grand scale, Denmark did it in the 90's to replace the old LORAN system for a more accurate system.  Survey your light houses (already done) put a GPS receiver up there and a transmitter. Then all you have to do is equip your ships and ferries with GPS receivers that can receive the error transmitted by the light houses.

 

[blw2]

Thanks for the post!  I have it in my watch list.

Just this past weekend on a walk on a wooded trail with my 10 year old daughter, I attempted (I think successfully) to answer her question in basic terms about what is GPS.  I have a Garmin Vivosport that I was using to track our distance. (it's basically a "fitbit" style pedometer with GPS and heart rate monitor).

I'll definitely pull up this video when my kids are available.  They'll probably say "this is boring" and flip back over to their youtube or games, but at least I'll try it.  Regardless, I'll find it interesting.

My first one was a Lowrance Airmap 100.  I don't even remember when or where I bought it....late 1990's I suppose.  It was awesome for situational awareness at the time, but looking at it now it's archaic... grey screen LCD with very basic graphics. Seems like it took forever to get a lock on enough satellites for a position fix before it would start working.  If memory serves me, they sold the same unit under a different name for marine use, and another for hiking/outdoor use.  You could download the databases for either type... but at the time I was interested in the aviation database...primarily (I think it was ) for the "nearest airport" function...or did it even have that feature?....

I think that I still have that unit in storage with my aviation stuff.  it may not even work... But if a museum want it for relic value, send me an IM!  ;D

 

[ELeland]

My first foray into navigation was a sextant and a pile of books as a reference for marine navigation.  Needless to say the only time I knew where I was was when I could see a landmark on shore.  Scrapped that idea.  Next was LORAN, best thing since sliced bread at the time.  That worked well until it was out of range I guess.  I had problems getting signals in some areas of the Bahamas, but had all my local reefs and hot fishing spots marked and it could get me back to them pretty close.  Then GPS, it's a great device.

 

[UTTransplant]

I was lucky enough to work with some of the finest GPS engineers in the world a few years back. The company I worked with received and decoded the signal from the first GPS satellite in 1977 when it was all still experimental. The program I worked on was a few decades later, but many of those GPS engineers were still working. I worked on both commercial aircraft GPS nav systems and military airborne and ground-based systems. The military stuff is so amazingly cool, but even the commercial stuff is astonishing in its accuracy these days. Funny enough, one of my sons is now working with the same company as a GPS systems engineer on weapons systems. Good job for a guy with a MS in Physics.

Fun stuff.

 

[Gizmo100]

I just can't help myself.........
My first foray into navigation was getting the map out of the glove box. Finding our location on the map and finding a route that would work for my Dad. All of this at about 10 years of age.

However refolding that DAMN map would get me in trouble almost every time.

 

[Larry N.]

I just can't help myself.........
My first foray into navigation was getting the map out of the glove box. Finding our location on the map and finding a route that would work for my Dad. All of this at about 10 years of age.

However refolding that DAMN map would get me in trouble almost every time.

Well, if you're going there, mine was map and compass in Boy Scouts, but this topic is generally about GPS nav, or at least it started that way.

 

[thelazyl]

As I recall it was the Soviet's shooting down of the South Korean airliner which prompted the US to open up GPS technology for civilian uses.  I am sure someone can keep me honest on this....

 

[PopPop51]

Brad,
My first plane, A Beech Sundowner, had a Northstar M-1 LORAN reciever. My second, a Piper Archer, had a whiz-bang King KLN-80 LORAN that had a "moving map" display (basically green lines and symbols on an otherwise black 3" CRT display).
LORAN was the grandfather of GPS, except that instead of using satellites at very high, line-of-sight radio frequencies, LORAN used groups of widely-spaced ground stations transmitting at low frequencies so the signal could carry over the horizon. LORAN had been in marine use since the mid-20th century. Because LORAN position information took nearly 30 seconds to calculate and the signals were easily disrupted by weather, it was only useful in enroute situations, though they tried to enhance it enough for use non-precision apporaches. But GPS overtook LORAN and rendered it moot.
IIRC, a KLN-80 listed for about $10,000 plus installation.

The whole concept of products getting both better and cheaper over time is a strange one to anyone born before. I'd guess, 1970.

 

[UTTransplant]

As I recall it was the Soviet's shooting down of the South Korean airliner which prompted the US to open up GPS technology for civilian uses.  I am sure someone can keep me honest on this....

GPS has always had a civilian component, but for many years the military kept an option open to make it less accurate in a time of war since the bad guys could use it too. They finally said they would never exercise that option so civilians could feel more confident about using GPS as a primary navigation sensor. The true military component in GPS is restricted from civilian use through encryption among other methods. It is much more accurate than the civilian version plus more resistant to jamming and spoofing (the ability of a rogue transmitter to pretend it is a valid GPS signal and thereby provide incorrect position information). Much more information than that and people would have to killl you. Not me though - my clearances finally expired a year ago.

 

[Larry N.]

As I recall it was the Soviet's shooting down of the South Korean airliner which prompted the US to open up GPS technology for civilian uses.  I am sure someone can keep me honest on this....

That occurred in 1983, well before GPS was available to the public. Although the DOD launched GPS in 1973, it wasn't fully operational until about 1995. 

During the 1990s, GPS quality was degraded by the United States government in a program called "Selective Availability"; this was discontinued in May 2000 by a law signed by President Bill Clinton. --- When selective availability was lifted in 2000, GPS had about 5 meter accuracy. The latest stage of accuracy enhancement uses the L5 band and is now fully deployed. GPS receivers released in 2018 that use the L5 band can have much higher accuracy, pinpointing to within 30 centimeters, or just under one foot.*


* This italicized quote is from Wikipedia -- I had to check if my memory was right.

LORAN had been in marine use since the mid-20th century.

LORAN was developed in the early 1940s (WWII), but was only for ships and some large aircraft at that time, since it was so cumbersome and time consuming to use.

 

[sueylan]

Thanks for sharing! It's agreat and informative video.

 

[Old_Crow]

LORAN was developed in the early 1940s (WWII), but was only for ships and some large aircraft at that time, since it was so cumbersome and time consuming to use.

The F4 I crewed in Thailand had LORAN.  The antenna was about 6 or 8 feet long, mounted on raised stanchions on the backbone of the aircraft(called a towel bar antenna by us mechanics). 
Late one night I was backing off the tail fin after doing my inspection for loose rivets, etc.  Caught the cuff of my pants on the end of the TBA and lost my balance.  Hit the wing on the way down and sort of rolled onto the flap.  Since there was no hydraulic pressure on the bird, the flap started down, and before I could recover I was sitting on the ground. 
And that's all I've got to say about LORAN.