Re: IFR with a VFR GPS

In article <1s7d2r38gp61i$.dlg@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
"Peter R." <pjricc@xxxxxxxxxxxxxxx> wrote:

> Ron Lee <nospamronlee@xxxxxxxxxx> wrote:
>
> > You should note that if you lose lock (too few satellites) then your
> > display will start flashing (or portions of it). That is not RAIM
> > which determines if you have a signal error.
>
> Just to clarify, are you saying that a *VFR* GPS's screen flashes when the
> GPS loses the required number of satellites for position calculation and
> that error is not a result of built-in RAIM?


When my hand held Garmin loses enough sats for position calculation, I
receive an alarm on the unit (both visual and audible).

I believe that RAIM performs a checksum to verify the integrity of the
data received from the sats. Hand held devices are indeed missing this
functionality, but it makes no difference for enroute, in my opinion.


JKG
.

Relevant Pages

  • Re: How many satellites are in geosynchronous orbit by now?
    ... There are also quite a few upper stages that were used to propel ... Most commercial satellites now have built-in ... apogee kick propulsion, but earlier sats and many modern Russian ... and U.S. military sats were kicked with upper stages like Blok DM, ...
    (sci.space.history)
  • Re: Question about 16-channel vs 12-channel GPS receivers.
    ... >>Are such receivers more accurate or stable in operation? ... > sats while dedicating channelto the EGNOS sats. ... is tracking two SBAS satellites and also has 12 regular satellites ... BTW, were these EGNOS or ESTB satellites, and will the EGNOS ...
    (sci.geo.satellite-nav)
  • Re: Why are some GPSs so much better than others?
    ... The number of visible sats is calcuable for any place on earth at any time ... satellites, but some don't rise over 5 degrees and many never rise above 20. ... building obstructions, topo obstructions). ... > 14ch is not a disadvantage, neither under open sky nor in a parking lot. ...
    (sci.geo.satellite-nav)
  • Re: Is SA selectively on (or off)?
    ... > with six satellites locked, the reporetd error was never below 150 ft; ... sats with high azimuth very rarely. ... This is caused by the fact that the sats ...
    (sci.geo.satellite-nav)
Loading