GPS Question

Un bel giorno mpm digitò:

Prior:

"1982 Civil GPS receivers introduced: Macrometer V-1000 and Texas Instruments TI

The first "cheap" (i.e. some thousand $) commercial receivers were made by Trimble in the half of the eighties.

Hmmm... It looks like the "GLOBAL POSITIONING SYSTEM WING (GPSW) SYSTEMS ENGINEERING & INTEGRATION, INTERFACE SPECIFICATION, IS-GPS-200, Navstar GPS Space Segment/Navigation User Interfaces" was first released to the public in Jan 1983.

"In 1987 DoD formally requested the Department of Transportation to establish and provide an office to respond to civil users? needs and to work closely with the DoD to ensure proper implementation of GPS for civil use." from

I did some work in satellite positioning in the late 1970's, pre-GPS. It was for a couple of offshore oil companies. One was Offshore Navigation Inc in New Orleans.

John

But, as you said, pre GPS.

There are some interesting trade-offs in receiver cost vs. satellite cost for the various available methods, not to mention system cost vs. acquisition times.

Damned if I can remember where I read up on it, though...

Best I can do is I have a Trimbel Placer GPS400 with 1993 date codes on the chips.

I know there was stuff available prior to that.

tm

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Well before, apparently:

Looks like '88 was right for the first _handheld_ GPS receiver.

But prior to 1988 they would have been using the Block 1 satellites:

Best regards, Spehro Pefhany

"The Journey is the reward"

eff.com

Thanks for all the research guys. It looks like it's not a strong argument. We likely won't use it in our response.

Do not remember when, but wasn't Trimble the first commercial GPS maker?

A contender would be Magellan.

Yes. So long ago I don't have it in my PC, but I did some minor analog stuff on the first Trimble chip that Arizona Microtek was designing. ...Jim Thompson

GPS World magazine just ran a great 2 part series on the history of the GPS design and implementation by some of the original players. I think it was May & June issues. Should be available online.

"Does anyone know when GPS signals first became available for use by private enterprise?"

When did 'Electronics & Wireless World' publish that minimalist design that turned the 'case of chips' approach into a basic RF stage plus some real-neat RISC software ?

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Hmm.. minus the crippling that reliever makers put in there to prevent it working too high or too fast?

To the best of my not sure knowledge it was avilable by the time they had 6 satellites in orbit out of a full constellation of 24. The problem at the time is that coverage was very spotty still and you could wait a couple of days to get a good fix. There was a change in poilcy to never use selective availability (which would drop off civilian use, but not military use, some time after 2002 i think).