GPS backup

[WDD]

Isn't WAAS stand alone? Then no "approved backup" is required, and anything is better than nothing.

WAAS is to create a signal enhancer, signal correction data - not a GPS signal. There are 38 ground based WAAS stations in the US, Canada, Mexico, HI. They don’t send a GPS signal out, just instructions to correct the existing GPS signal. That signal goes up to the geo sync satellite, which is what our GPS units talk to to get the correction signal.

So if GPS is jammed, the WAAS isn’t able to help.

 

[TCABM]

…So if GPS is jammed, the WAAS isn’t able to help.

Or otherwise unavailable.

 

[Salty]

WAAS is to create a signal enhancer, signal correction data - not a GPS signal. There are 38 ground based WAAS stations in the US, Canada, Mexico, HI. They don’t send a GPS signal out, just instructions to correct the existing GPS signal. That signal goes up to the geo sync satellite, which is what our GPS units talk to to get the correction signal.

So if GPS is jammed, the WAAS isn’t able to help.

I don’t know what happened, but I never posted what’s in the quote box with my name on it.

 

[WDD]

I don’t know what happened, but I never posted what’s in the quote box with my name on it.

That’s just odd. You indeed didn’t post that. Someone else did. How was that even possible?

 

[dtuuri]

I don’t know what happened, but I never posted what’s in the quote box with my name on it.

Yeah! That was MY post! But you might agree that with 592 AM radio stations in Florida it would be nice to have a simple device that keeps a running estimate of your position by utilizing them as a backup to GPS. https://radiostation.info/am/florida/

 

[Greg Bockelman]

That’s just odd. You indeed didn’t post that. Someone else did. How was that even possible?

A quote tag got deleted somehow. It can happen when one deletes part of a post they are trying to quote.

 

[Palmpilot]

Yeah! That was MY post! But you might agree that with 592 AM radio stations in Florida it would be nice to have a simple device that keeps a running estimate of your position by utilizing them as a backup to GPS. https://radiostation.info/am/florida/

I guess a DF antenna could be installed for that purpose. The receiver would need to have a database of station frequencies and locations. The receiver would need to know the last GPS position in order to differentiate between broadcast stations on the same frequency.

 

[TCABM]

Sure, If you have nothing else, all bets are off and the rules don't matter.

Your comment and article earlier prompted me to go back and read the AFMS for my GTN650. Thank you.

Amazingly, the Abnormal Procedures section describes the outcomes when there’s a loss of GPS/SBAS Nav signal and what actions to take; same for approach downgrades.

 

[midlifeflyer]

Amazingly, the Abnormal Procedures section describes the outcomes when there’s a loss of GPS/SBAS Nav signal and what actions to take; same for approach downgrades.

Not so amazing since "here is where we think you are" mode has been there since the GNS-WAAS models

 

[dtuuri]

The receiver would need to know the last GPS position in order to differentiate between broadcast stations on the same frequency.

Brainstorming with you, why is GPS needed? Each location, say pixel on a map of, say, Florida, would have one set of theoretical bearings that should exist over that point. So, the device would only need to find the pixel with the highest number of matching bearings — and there's where you probably are. No?