Barometer Measure Drops


Would you know what could be wrong with this barometer measurement? I am using copter 3.5.5 with Cube Black. Looking at the rangefinder values I was expecting the barometer to follow it closely. But there is a sudden drop for the barometer. This was a test mission flight where the copter took off 3 times and landed.

Should I worry about anything?

Did you observe the drone lowering its altitude in these flights? i.e., did it appear to be following the barometer altitude or rangefinder altitude?

Upload the flight log .bin and we can take a closer look.

Log is on DropBox

FYI, it was a Terrain mission with terrain following. So it was using the rangefinder to keep 20m altitude above the terrain. But for some reason the barometer shows a very different measurement.

Kind regards,

Oh. If it was maintaining altitude using the rangefinder, then the barometer (and EKF altitude) will go up and down as the drone follows the terrain. This is normal, as the barometer and EKF altitudes are not expressed as above ground level, they are relative to the EKF origin, which is usually near your takeoff point.

You can check what the EKF thinks is height above ground level with the NKF5.HAGL log field: