Thread: About 37xx converted to 34xx satellites reception accuracy

@giuseppe66

You may possibly be on to something there i reckon.

WAAS is used as an acronym internationally, and it's actually the name of the original GPS accuracy augmentation system developed by the US FAA for improved vertical and lateral precision in aircraft approaches. I think it's more correctly called SBAS (Space/Satellite Based Augmentation System) internationally and I also think it's normally enabled by default in most modern units (e.g. my old StreetPilot 2610 also lets you turn WAAS on or off).

Could this be at least partly the problem with 37>34? Maybe WAAS is not working properly or at all when using 34 fw on 37 hw? It would explain the extreme variation in elevation readings I experienced in that test run. Also, again i think WAAS more effectively enhances the moving accuracy in a vehicle/aircraft. Moving accuracy was much worse in my tests than when stationary.

This is just another 'hypothesis' of mine. Ready to be shot down in flames by the Software Experts in the interests of keeping this discussion going ..... fire away!

EDIT: Another thought on this, note the differences in satellite displays between 3790 and 3490 in my two pics. 37 is locked on to 24 in both pics, 34 is not. In pic 1, 34 is using 153 but 37 is not. In pic 2, 34 is using 19 but 37 is not. WAAS/SBAS i think has someway of knowing more quickly than a non-enhanced GPS if a sat. is 'off' in that it's giving incorrect info., and ignores it.