DWM Calibration

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vpaesmans
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DWM Calibration

Post by vpaesmans » Wed Dec 21, 2016 3:28 pm

Hello.

Do you plan to have pre calibrated deck and nodes?
I noticed that the default antenna offset in the code is not correct and seems DWM1000 dependent.
If I place one deck close to 1 node, I get a distance of -0.9.
The offset in the code does not seems to be in meter when I change it to of a good result.

Thanks in advance.

Vincent.


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arnaud
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Joined: Tue Feb 06, 2007 12:36 pm

Re: DWM Calibration

Post by arnaud » Wed Dec 21, 2016 4:51 pm

Hi Vincent,

The calibration in the firmware is a very rough measurement done quickly so I am not surprised it is not very accurate. It is good enough for TWR fligh, mostly when the Crazyflie is surrounded by anchors.

The accuracy of the measurement seems to be dependent of the RX power so I have seen more non-linearity bellow 1m.

Are you seeing a big discrepancy between anchors? I know the calibration is off but I did not see much difference between anchors. What offset are you changing in the code. Isn't is about 150m?

Assuming the antenna delay is quite similar between anchors, it does not affect TDoA measurements.

To answer the question there is currently no plan for pre-calibrated board. Though both decks and nodes have memories so they are able to store individual calibration values.

/Arnaud

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