<p>The ArduPilot uses a NED (North-East-Down) axial orientation. This tells you  which direction gives a positive value.
If you see a negative Z value, that would indicate the Quad is taking off. When landing you should see a positive value.
Note that these 'directions' are based on the orientation of the PixHawk in relation to the Quad itself. So 'North' would be the front of the Quad.</p>

CC BY-SA 4.0
2021-08-16T18:12:44.037Z
2021-08-16T18:12:44.037Z
Kevin
<p>I was using pix hawk with Ardupilot : I want to know which frame of reference is used in pix hawk - Ardupilot - H configuration</p>
<p>when I am observing the valued in the logs the Acceleration Z is showing -10m/s^2</p>

<autopilot><airframe>
Ardupilot Frame of Reference for X-Quad
Lawliet
# Ardupilot Frame of Reference for X-Quad

(Asked by: username_0 on 2021-07-16)

I was using pix hawk with Ardupilot : I want to know which frame of reference is used in pix hawk - Ardupilot - H configuration

when I am observing the valued in the logs the Acceleration Z is showing -10m/s^2

**Tags:** autopilot, airframe

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## 1 answers

### Answer by username_1 on 2021-08-16. Score: 2

The ArduPilot uses a NED (North-East-Down) axial orientation. This tells you which direction gives a positive value.
If you see a negative Z value, that would indicate the Quad is taking off. When landing you should see a positive value.
Note that these 'directions' are based on the orientation of the PixHawk in relation to the Quad itself. So 'North' would be the front of the Quad.


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