A few issues in my last Mavic Pro (1) flight

[John Cutrone]

I flew a couple of months ago without any problems after tracking down a compass error.  I went up again today and ran into a large number of errors being reported on my flight.

A.  Some of the errors that showed up on the flight an which show up when I replay the flight on the iPad from which I run DJIGo4 do not show up on the replay of the flight on Airdata.  Among them are: 

1.  IMU heading error, please restart aircraft; 

2. weak signal warning; 

3. weak GPS signal, positional accuracy may be compromised, please fly with caution; 

4. weak signal, adjust antenna and avoid signal block; 

5. strong interference to remote controller, signal interruption maybe more likely, fly with caution;

When I play the flight on Airdata, some of these show up in the flight data but without an associated warning on the Airdata replay, e.g. at times the signal strength shown is 75% or 80%.  Will that cause a weak signal error?

On the Go4 App replay, I see that when I get the weak GPS signal error, while the App is reporting that 16 satellites are locked, some or all of the four bars for signal strength are grey rather than white as when there is a strong signal.  Curious as to why I would have some many satellites locked and strong in one instant and then weak the next and then back to strong.  There were no clouds to speak of at this point though there were some moving in but some distance away (though not overcast) and I can't think of any other cause for the GPS signal to get weak.  Thoughts?

As to the weak signal, adjust antenna warning and strong interference to remote controller warning, both came on without warning even though i had not changed my position or the position I was holding the controller or the way the antenna were standing, and then just as suddenly, the warnings disappeared.  Any idea why this would happen?

My favorite is the IMU heading error, please restart the aircraft.  First, every time I see this error, I just about mess my pants, but second, how the heck are you supposed to restart the aircraft when it is 100+ feet up and several hundred feet away?  Or is there something I am missing here?  And then that error too disappears and the flight continues normally.

The Airdata upload for this flight appears at: https://app.airdata.com/share/gzCqFO

Can anyone take a look and help me figure this one out?  As I say, this is the second time I have flown it since tracking down another compass error a few months ago and flying several flights without issues.

 

Any help would be greatly appreciated,

Jack

[Steve]

Make sure that you have correctly calibrated your IMU and the compass, if they dont agree the drone can behave unpredicatbly, also make sure there is no magnetic field or ferrous material around, some concrete has sufficient rio bars to upset the compass, I have had issues with incorrect compass calibration that caused mine to fly away, I was close to the ground so able to command it to land. In the compass calibration there is a set of gauges that indicate the success of both compasses, there appear to be 2, probably uses best of either. Also I incorrectly calibrated the IMU by placing the bird on the wrong side, best to do it slowly and carefully. 

I use the Litchi app for my flying, I prefer the interface it seems to have less warnings than the DJI app. your signal strength seems fine I often have signal stregth down to 72% with no issues. Although when I am a long distance I have seen loss of downlink meaning the video gets very choppy and laggy, 13 GPS satellites is OK .

Was there likely to be any strong WIFI signal in the area Occulus operates in the 2.4GHz range and strong WIFI can affect the signal watch this for info on channel settings https://www.youtube.com/watch?v=lU61vNmhHL4

Hope this helps

Steve