NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Dip-meter again
From: Lu Abel
Date: 2012 Apr 12, 11:21 -0700
From: Lu Abel
Date: 2012 Apr 12, 11:21 -0700
And let's remember this was a ONE-channel receiver (ie, it can receive and process signals from only one satellite at a time. Compare that to today's 2 mm x 3 mm chip that provides a full 12-channel receiver!
From: Richard B. Langley <lang@unb.ca>
To: NavList@fer3.com
Sent: Thursday, April 12, 2012 4:58 AM
Subject: [NavList] Re: Dip-meter again
Is this the photo?
http://www.gpsworld.com/gnss-system/gps-modernization/the-origins-gps-part-2-fighting-survive-10010
-- Richard
On 11-Apr-12, at 5:54 PM, Lu Abel wrote:
> If you read the history of GPS, soon after Sputnik's launch American scientists figured one could get positional data (maybe only a line-of-position, not a fix) from the Doppler shift in a satellite's signals. This resulted in a very hush-hush project that resulted in the Transit system. Multiple US defense projects then looked for a next-generation follow-up. Fortunately (at least for the modern world) the projects were merged with the best ideas from each being selected as the projects consolidated and moved forward. One specific I remember is that one of the projects proposed that the receivers contain an atomic clock! For 1960s or early 1970s technology, not unreasonable -- we had not seen the dramatic effects of shrinking semiconductor technology. Fortunately, that got changed. There's a wonderful picture of a soldier wearing a full backpack with a large antenna sticking out of it. It's a single-channel GPS receiver! (wish I could find a copy to attach, but I can't)
>
> From: Alexandre E Eremenko <eremenko@math.purdue.edu>
> To: NavList@fer3.com
> Sent: Tuesday, April 10, 2012 11:14 AM
> Subject: [NavList] Re: Dip-meter again
>
>
> Richard,
> Thanks.
> Do you know how accurate it was?
>
> > The first TRANSIT satellite was launched in 1961. The system was
> > declared operational in 1964 and became classified. In 1967 it was
> > declassified and became available for civilian use.
>
> Alex.
>
>
>
>
>
>
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