I am wanting to fly my Inspire in conditions where GPS control is not advantageous - under large trees where signal is lost frequently.  What I have determined so far is that Atti mode looks like the best approach (I like the vertical control).  I do not want the possibility of the RTH (or any other similar feature) kicking in as I will be following a trail and not ending up in the same place where I start from.  The safest approach will be to put the bird is at wherever it is at that momment.  In other words, I want full control and don't want it to be overridden by any automatic function.  I normally fly with full GPS mode and control so this is a new approach to me.  Does anyone have any thoughts on how best to approach this?

Your flight scenario is very similar to flying indoors. There are about 15 related topics across the forum.

One of the ones to start with would be DJI-TIM's tutorial thread.

As you suggest:
1) Turn OFF RTH first thing! We don't want our aircraft climbing up into the trees.
2) Put the aircraft into A-mode, you don't want occasional GPS to be switching you back and forth between P-GPS and P-ATTI (crash waiting to happen)
3) Analyze your flight path looking for  VERY confined bottlenecks as these will take constant concentration. Don't over-correct, but anticipate the aircraft movements when flying in ATTI mode
4) Analyze what VPS will be seeing within your filming environment and enable it or disable it depending on its benefit
5) After a while, I found that there was a "best" altitude for controlling the aircraft. Too low and ground effect was bad or adequate room for maneuvering was limited. Too high and you're into the rafters or trees.

terrylewis Posted at 2016-4-2 05:27
Your flight scenario is very similar to flying indoors. There are about 15 related topics across the ...

Thank you!  That is awesome.

I am just running a small test.  I have turned the "RC Signal Lost" to Hover from RTH and have turned off the "Smart Return Home" function.  Is there anything else?  Also, should I still calibrate the compass?  I read one thread that recommended still doing this.

tworivers Posted at 2016-4-2 05:41
Thank you!  That is awesome.

I am just running a small test.  I have turned the "RC Signal Lost"  ...

The simple rule for compass calibration is to calibrate your compass when it's needed. Well, that's double talk!.......   When is it needed?

The compass sensor is a three axis device that measures x (north/south); y (east/west) deviations and z, vertical inclination. We should always calibrate the compass the first time we fly in a new area. And possibly after firmware upgrades. We simply calibrate by rotating the horizontal and vertical axis of the Inspire with no magnetic influence within 5 meters of your aircraft (absolutely no metal).

With this first calibration, we should inspect and record the Compass sensor MOD value under MC Settings/Advanced Settings/Sensors in the GO App. The MOD value should be around 1500. Fly your aircraft conservatively, expecting to switch to A-Mode if necessary. If the Compass MOD value is around 1500 and the aircraft flies well, then your calibration is a keeper. You won't need to recalibrate unless the MOD value increases or decreases significantly, or you move to fly in a new location. DJI says about 150 miles because the earths magnetic variation changes at about that distance.

So what the heck is this MOD value?

DJI gives us a statistical measure of our calibrations within the GO App under MC Settings/Advanced Settings/Sensors for the gyro, the accelerometer, and the compass. If we watch these values with each flight, we will know if our IMU or Compass needs recalibration.  These sensor readings include the three axis readings but the fourth column is the one that matters. The MOD values are "Root-Sum-Square" measures of the accuracy of your calibration. The three compass values should always generate a MOD around 1500. Always check your sensors before takeoff and when the aircraft is level, look for MOD values of 0.00 for gyros, 1.00 for acceleration, and the compass fluctuating around 1500. If it's significantly different, you need to re-calibrate.... Simple!

Best of luck with your test and always Fly Safe!

terrylewis Posted at 2016-4-1 18:04
The simple rule for compass calibration is to calibrate your compass when it's needed. Well, that' ...

    Terry Lewis, I love reading your explanations, you do it in in a clear concise  manner.  I also appreciate that  with your level of technical expertise you dont come off as arrogant.  I learn a whole lot  from your Post and really appreciate your contributions.  Many of them I cut and paste to a "DJI" folder that I keep good ideas in.   Also you and I were working on a Forum Members "Bricked " RC  Transmitter and with a folding in  of your Idea and a folding in  of mine , the download with a thumb drive  with C1_FW_V01.05.0080 has solved several Forum members "Bricked " Transmitters .  I had a man in Germany e-mail me last night exclaiming  that this solved his challenge.  He had spoken with DJI and they said there was nothing that could be done and he must send it in, he was gratful because it saved him time and money.  Also, I made a Tutorial which is on the thread : "Bricked RC Solution " and I gave you credit for the fix as well.   

Well done Terry !

Cheers -  donnie