Looking for Trouble ??

[Fifty7]

Hey Fifty7, if those tanks are going to be demolished for a new mall, that's a great opportunity to do a time phased video. With Litchi, setup a flight path that you fly over and over, identical flights through the next year as the mall is being built. After the mall is done, edit short sequential clips from each flights into single video that shows BEFORE footage in the beginning of the video, and as you fly around, the end of the video shows AFTER footage, showing the finished mall. Time phased videos are intriguing. Yes, it's a lot of work, but it will be epic in the end. Here's an example below of a "day to night" time phased video using Litchi. In your case it would be month to month time phasing. I wish I lived in the East so I could do a "Season to Season" time phased video with tree color, complete with snow.

Pretty cool. I've never tried Litchi and really never wanted to. I like flying myself but for something like that I may have to try it. As for the tanks, nobody knows what's going on right now. They've been talking about it for years. Recently they built up the dirt around the tanks and took a lot of dirt or from other areas of the site but they've stopped again and haven't been there for months now so who knows.

I needed advice calibrating near water and someone shared the post below with me. You may find it helpful:

http://www.phantompilots.com/threads/compass-calibration-a-complete-primer.32829

Thanks. Will take a look.

57, I've flown over them a few times. Never a problem. I launched from the Lowes parking lot early on a Sunday morning and flew over the tanks, out to the landfill and back along the Kill Van Kull.

I drive by there every day. I was thinking about going down the road to the golf range but Lowe's is a good idea. This was from Industrial Loop. Had to go over the prison which would explain my warning about the area I was flying in. [emoji16]


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[Razorback1]

Actually, this can also be a problem. The P3 gets it's heading info from a combination of sensors; mostly the gyros, then the accelerometers. Shortly after motorStart the Flight Controller initializes the Yaw value based on the compass magnetometers but after that it is info coming from the gyros and accelerometers that determine Yaw. The magnetometers have only a small effect on the value of Yaw.

If the P3 launches from a man hole cover that initial Yaw value will be incorrect because of the geomagnetic distortion and it's effect on the magnetometers. When the P3 clears the effects of the man hole cover the compass/magnetometers become correct, BUT the Yaw is being determined by the gyros which hasn't changed.

Here's an example of where that happened

The P3 was launched from a concrete driveway that contains rebar. magYaw is a diagnostic value calculated from the magnetometers. magYaw and Yaw (the value that the P3 uses for heading) are the same incorrect value until the P3 launches at time 7.4. Then magYaw (blue line) changes to -162, the correct value, BUT Yaw stays at the old, incorrect, value of -27. You can also see the effect on the magnetometers (red line) as the P3 leaves the effects of the rebar. This is the reason that a COMPASS_ERROR_LARGE is declared (denoted by the blue background).

Later, at time 71 the COMPASS_ERROR_LARGE had been replaced with a YAW_ERROR_LARGE

The pilot initiates RTH shown off-blue background but the P3 still has incorrect Yaw info. The P3 then towards what it thinks is home. It was 2 minutes before the Yaw was finally corrected.

Thank you for posting this valuable information, i have been launching from a concrete pad and have been having these troubles but luckily havent lost a drone,I know now whats causing it[emoji1360]

 

[BudWalker]

Thank you for posting this valuable information, i have been launching from a concrete pad and have been having these troubles but luckily havent lost a drone,I know now whats causing it[emoji1360]

Something I've started suggesting is that prior to flight confirm that the heading indicator in the Go App map display is correct. If it doesn't agree with you can see visually then don't launch. IMHO this is the single most effective measure to prevent launch time fly aways.

 

[happydays]

Hey Fifty7, if those tanks are going to be demolished for a new mall, that's a great opportunity to do a time phased video. With Litchi, setup a flight path that you fly over and over, identical flights through the next year as the mall is being built. After the mall is done, edit short sequential clips from each flights into single video that shows BEFORE footage in the beginning of the video, and as you fly around, the end of the video shows AFTER footage, showing the finished mall. Time phased videos are intriguing. Yes, it's a lot of work, but it will be epic in the end. Here's an example below of a "day to night" time phased video using Litchi. In your case it would be month to month time phasing. I wish I lived in the East so I could do a "Season to Season" time phased video with tree color, complete with snow.

Like this?