On 2/2/2011 2:29 PM, bownes wrote:
Of the 2 lc orgs I administer or am a member of, and the roughly 8 other lc
orgs I interact with on a regular basis, only one uses lc certified gps equip.
The others are all consumer grade or don't use gps.
However, a slew of filings and letters from the lc community might not be a bad
idea, if only to lay the groundwork for the inevitable lawsuits.
Pardon my ignorance, but I can't immediately work out what you mean by 'lc'.
On Feb 2, 2011, at 3:06 PM, Rex<[email protected]> wrote:
On 2/2/2011 7:25 AM, jimlux wrote:
I got the impression that it wasn't modeled, but was an actual field test of
some sort. I'll have to go back and reread.
But, it's possible that the consumer receiver has better multipath and
interference rejection, if only because it's newer. Aviation stuff takes longer
to go through the approval cycle, so it tends to lag consumer electronics in
terms of technology adoption.
From the paper submitted by the GPS manufactureres to the FCC
http://www.gpsworld.com/gnss-system/signal-processing/lightsquared-jamming-report-11030
it seems they simulated the Lightsquared signal with test equipment and made
measurements in an anechoic chamber of effects on GPS signal reception to a
couple of popular GPS receivers. Using this data they extrapolated real-world
effects with path loss calculations. Ironically, it probably wouldn't be legal
or safe to make the jamming measurements in a real, open space, environment.
The paper says the Lightspeed transmitters can be up to around 15 kW EIRP in a
band right adjacent to GPS. I would think filtering out that signal to avoid
overload would be a daunting task.
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