Large Deviation in Magnetic Interference

Hey all,
I was doing some testing with a Cube Orange and Here3 unit (as a sensor payload) around some power lines and an electrical sub-station last week. The goal of the experiment was to look at different loads on varying power lines and see how the magnetic fields produced would interfere with the compass and hardware.
We completed two tests on a very minimally loaded line.
I have been looking at at the magnitude of the MagX, MagY and MagZ (sqrt(x,y,z)). What I believe I should be seeing is a relatively horizontal line with small variation, depending on the level of magnetic interference.
In the picture below I have graphed the magnitude and the altitude for reference.
You can see the large ‘steps’ in the magnitude at the start, middle and end. These line up with the aircraft yawing ~180 degrees. The dips in the altitude around measurement number 1220 (x axis) are us lowering past the line and raising back above it twice. Then we yaw 180 degrees and face the rear of the aircraft towards the line, this is where we see the large step down.
image

I’m a bit lost as to why the aircraft yawing is causing this big step down in magnitude. Ive looked at other flight logs where we are yawing and the magnitude stays horizontal without steps.

The second flight we did also had us yawing but didn’t have the step effect.

Any ideas? Ive attached the bin log for the flight.

first thing i notice is COMPASS_ORIENT is set to 6. = yaw270

how is the here mounted?

Hey Michael,
The Here3 was mounted with a 270 degree offset (facing to left side of aircraft).
We used a smaller aircraft to carry this as a payload and the Here was mounted on top of the aircraft. It was near the battery and I expected to see some interference because of this.

Joe

Just a side note i’ve learn too stay clear of high power lines had many decent flight in a field near my Home got a bit to close to the lines and fly away occurred! Happened twice got a bit expensive with repairs!! :dizzy_face: 100 yards is a good distance to keep away from them wires!!

im not sure if this will change anything but try disabiling
COMPASS_AUTO_ROT