Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!wuarchive!udel!haven.umd.edu!mimsy!steelmill.cs.umd.edu!rusty
From: rusty@steelmill.cs.umd.edu (Rusty Haddock)
Newsgroups: sci.electronics
Subject: Re: GPS system receiver
Message-ID: <34617@mimsy.umd.edu>
Date: 17 May 91 20:16:46 GMT
References: <0iP121w164w@ersys.edmonton.ab.ca> <12780006@hpuplca.nsr.hp.com>
Sender: news@mimsy.umd.edu
Reply-To: rusty@steelmill.cs.umd.edu (Rusty Haddock)
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 37

In article <12780006@hpuplca.nsr.hp.com> jeff@hpuplca.nsr.hp.com (   Jeff Gruszynski  ) writes:
   >> / hpuplca:sci.electronics / lharris@ersys.edmonton.ab.ca (Leonard Harris) /  8:17 pm  May 15, 1991 /
   >> Hi.  Does anyone know what would be involved in building your
   >> own global positioning satellite receiver?.  i know the frequencies 
   >> they transmit on, but what data does it send.  Also more than one 
   >> satellite has to be interrogated to calculate position.
   >> Any ideas?
   >> thanks /len
   >> 
   >> Leonard Harris              lharris@ersys.edmonton.ab.ca
   >> Edmonton Remote Systems:  Serving Northern Alberta since 1982
   >> ----------
   >
   >	In my previous life I worked with military satellites including
   >	GPS.  I once considered building my own receiver, so I called up

In one of my previous lives I worked on Texas Instruments' TI-4100.  This
was a heavy box with somewhere around a dozen 4"x5"(?) PCBs in it with 2
CPU's handling receive and navigation/user interface functions.  There
was at least one other CPU for the tape deck too.  Still, that box was
designed at least 10-years ago and was meant to go almost anywhere from
the tropics to the polar regions and out to sea on an oil rig.

   >	On the other hand I've heard a division of Rockwell Int'l is planning
   >	to come out with a ~$250 personal GPS receiver.

It's about time.  I believe this is a single card that fits into a
IBM/clone-PC.  I don't know if this includes the antenna and if it's C/A
only or if it can do P-code as well.  I think it'll only track 4
satellites too but that's all you need for lat, long, alt, and speed.

	-Rusty-
--
Rusty Haddock / Computer Science Dept	DOMAIN:	rusty@mimsy.cs.umd.edu
University of Maryland			PATH:	{uunet,rutgers}!mimsy!rusty
    If someone points a quad-vectored, hyper-thermic, cosmo blaster
       at you it's a safe bet that you're about to become toast.