Regarding re-calibrating your IMU....for clarification I meant that if you have a good calibration at a particular location by all means keep it. Do not calibrate inside the structure but outside if you have to. Although I do not recommend taking off from a person holding the UAV up in the air, DJI has a procedure for the Phantom vintages to do so. I would never ever think of it with an I1. Hold on to one if you are wondering why. Any place you hold the I1 there is less than an inch in clearance from your finger not to mention the booms are going to articulate while TRYING to hold it. I can't think of a worse idea but I have first hand knowledge of a failed attempt.
There are so many variables that I could add to this all day. Consider the sense and avoid, when you are in a metal building you almost never be able to use it. One because you will be most likely be in ATTI mode, two because you will make your own interference with the hypersonic Vision Positioning System bouncing off metal and compromising your own communications. The sense and avoid in some buildings, will do the same thing, cause self induced issues communicating.
For the record, I didn't intend to be vague by describing "issues" as the problem to watch out for. I used the word because it is the best I can do as I know what happens when you get inside metal buildings such as a generating facility of most kinds. Coal, natural gas, water powering the turbine, it doesn't matter, the UAV turns into a squirrel (a flying squirrel) that you chase with your mind and you have good days and bad. The good days you change the battery every 20 to 30 minutes. The bad days, you got outwitted by an electronic squirrel of the woodland variety and you go home wondering where the flying squirrel went.
A digital ground control station is the probable answer. As I mentioned previously, there are no contemporary off the shelf UAV's that can handle the rigors of frequencies that a generating station will throw at you. Or did you throw it at yourself? It can be maddening and I would love for someone to tell us they have a solution. And by solution I don't mean a drone in a cage that we bounce around like a super ball off an aluminum bat. We are looking for smooth controlled flight like the kind we have come accustomed to piloting outside without the super subtle footnote. ** metal may cause variations blah blah blah
So if you refer to the Kp index before each flight, out with your secrets Mr./Ms. Hawking. We are reasonable people that just want an answer as to what steps need to be taken. Feel free to speak in a condescending tone, we will get over it. It beats rocking back and forth with marbles rolling around inside our hollowed out melon.
But whatever you do please help us above average, decent and kind members of society who are being driven absolutely mad by the complete lack of reference for indoor flight (with control). PLEASE!