GPS and Beyond: The SatNav Transition for aviation

On Tue, 21 Sep 2004 03:11:27 +0000, UltraJohn wrote:


On Sun, 19 Sep 2004 17:00:12 GMT, R. David Steele
steele.david@verizon(DOT)net/OMEGA wrote:

GPS and Beyond: The SatNav Transition June 18, 2003
By Ross Bowie


snip
somethingggggoing to make a prediction.
Within 20 years we will no longer depend on GPS for navigation, at
least not as the primary, or sole means of navigation toward which we
are currently moving.

We already have some pretty good solid state gyros and inertial
systems.

I'd bet that we are going to reach a point where we will be able to
have small, compact, and inexpensive systems that will be independent
of outside sources except for possibly "correction, or reference
points". those points could be GPS and/or widely spaced ground
stations.



According to my "SR-71 POH" it used and INS with star mapping to correct
it. They have improved tremendously in the optics and microcontroller
since that system was devised so I would think you could use something
like that today without to much trouble.
John

Sure, if you can fly high enough so the stars are visible during daylight.
Otherwise, this will only work at night and if there isn't too much cloud
cover.

--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/
e-mail: khorton02(_at_)rogers(_dot_)com

From: Jack Yeazel
Date: 9/22/2004 8:03 AM Central Daylight Time
Message-id:



Bob Noel wrote:

In article ,
wrote:

Eunometic,

-It would be independent of an expensive satelite constellation.

No. It needs initial position information.

It most definitely can be independent. The initial position does not
have to be determined by a sat system.

OK, but then by what??
--
Jack


The various INS systems I worked on in the Air Farce could be
updated/initialized manually. There is a memory that would keep the location
and direction information at time of power off. The older systems I worked on
had magnetic core memory.

The INS can determine true north all by itself, but uses compass information to
give it an approximation to speed this process.

Dan, U.S. Air Force, retired