iFly GPS Forum

Just pulled out my old phone (Samsung S7, running Android 8). There's the same approximate 50' discrepancy between GPS Status and GPS Essentials on that phone. Just like on my Samsung S21+, GPS Essentials is consistently 50' too low. Presumably, iFly would be also, but due to license restrictions, I can't run it now on that old phone.

In comparing the same apps to each other across phones: they're in agreement with each other (each app agrees with the same app on the other phone, give or take 10').

So, if this is a problem with the altitude data that the API provides iFly (and presumably GPS Essentials), then this is not an Android 12 problem -- it's been there for awhile.

It may be a red herring. But I was saying that I agreed with you that the altitude reported by iFly was lower than it should be from what I could see on both my phones.

I'll do some more research on Fri or Sat, when I fly. It might be a big nothing-burger, but It's possible that you've uncovered an overlooked issue with the altitude that's being provided via the API that iFly (and probably some other GPS-using apps like GPS Essentials) are using to get GPS data.

I agree with you that iFly is probably reporting what it's getting from whatever source it is currently using. But there's two different things going on in your last post. In the first case of your testing, iFly is reporting what it's getting from the Pixel and the tablet hardware via a blackbox programming interface it uses (aka an API). In the second case, it's reading a stream of messages it's getting from the Stratux. Two different things. The Stratux may have a better (or not) GPS receiver, and/or it may be that it's updating iFly less often than the API allows -- so less jumpiness. But the important point is that when connected to the Stratux, iFly is not using the API to get its GPS info.

What I've been questioning is whether the API is providing correct altitude information. It has already been shown to not be working right in regards to providing the most accurate horizontal position information available when in "fuse" mode. And, iFly (when using the API) is reporting a lower altitude than what Google tells me my home is at. And, that altitude is lower than what another GPS app on the same device is reporting. So, I have a shadow of doubt whether it's been passing accurate altitude info. It probably is, but I'm going to test some things.

If there is a problem, I suspect the API and not the iFly app because I have a third GPS app that 100% agrees with iFly in regards to altitude -- both of them being low, and both reporting the same altitude to the foot. I suspect they use the same API. This behavior was consistent for these apps on 2 different phones.