Help Diagnosing GPS issue (not a bug report)

My copter has an issue w/ the GPS I cannot figure out. This isn’t beta testing related, so I don’t know if this is the best place to ask, but I am running 3.4.

Others have been able to see from my logs that the GPS is bad. But I don’t know what they are looking at.
I’ve replaced the GPS and have the same results.

I’m wondering if the communication between the GPS and flight controller is the problem, or just the signal the GPS is receiving in my location. (different copters with the same GPS work, though)

Someone looked at the problem I was having and said:
The GPS quality is very poor with large velocity errors as evidenced by large values of reported speed error from the receiver (GPA.SAcc) and large velocity innovations from the EKF. The EKF was rejecting GPS velocities for much of the time.

I cannot find any info in google about the “GPA” logging, and how to interpret it.

I’m really stuck on this… Like I said, I replaced the GPS and it still does it… Other copters in the same area work fine. I’ve turned off all other radios on the copter, and the logs still look the same. I occasionally get "gps is not maintaining 5hz update speed (or something similar) prearm warnings… But it’s random… other times it works fine. (And I don’t really know what that error means… I’m assuming it means the GPS is not communicating w/ the copter properly, and has nothing to do w/ GPS reception in my area, but I don’t know)
If you’d like to see a log, this is the post I initially made (There’s a log attached if you follow the link):
I’ll be happy to do some flights and log more data if it will help… But I need some advice on what to look at in the logs and how to interpret the data. (I just know to look at #sats and HDOP, and those are fine)
Thanks for any help.

Do you test rc5?

Alright, I’ve mostly solved this.
The issue has mostly been my 1.2ghz video transmitter… It’s only 200mw and is on the opposite end of the copter from the GPS. But it’s still causing interference. (It’s a small copter, so can’t get much separation).
I have 2 copters built on the same frame, both 1.2ghz video… The video tx w.out any trouble is a bare/naked PCB and wire antenna… The one with the problem is the same wattage, a completely enclosed PCB and a proper antenna… But it’s much worse! I would have expected the opposite. (I guess the circuit itself is worse on the enclosed one)

But, even with just the pixracer, the signal drops…

So, powered via USB, I get 14 satellites.
Powered by battery and video transmitting, 6 satellites.
Powered by battery and NO video, no accessories of any kind powered, only the pixracer and its power module, 10 satellites. I unplug the battery and it immediately goes to 14.

So, that leads me to believe something with the power module is interfering w/ the GPS a little… And the video TX was interfering a lot.

I guess it’s time to try that 3ghz video system…