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4 connected wooden bars with photogrammetric markers to be mounted with the acrylic plate onto the tripod
2. Important advice
Please handle the whole equipment with care
In particular avoid scratches or dirt on the photogrammetric markers
The calibration should be carried out in a free space with at least 4 x 4 meters
The weather conditions need to be good, with sunshine but no wind
Any oscillation or movement of the equipment during the video capture will affect the data quality
avoid touching the equipment during calibration
avoid any wind
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Unfold the tarpaulin and put it in a sunny place. This is important as the black parts should heat up in the sun so we can later see a contrast in the IR camera between the white and the black parts:
To unfold the wooden bars, release the nut from the screw and remove the top washer:
Put the bars in form of a cross with 90° spacing between the bars. Then carefully tighten the nut again (NO TOOLS REQUIRED):
Setup the tripod by spreading its legs and pull out the first inner stage to raise the tripod
open the clamp and mount the cross with the reference system to the tripod.
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Carefully close the clamp and make sure everything is tight. The cross should now be situated horizontally some 40-60 cm from the floor.
Arrange the bars in a star shape around the tripod as indicated in the next picture. The exact location is not that important, but the equal spreading is very important:
The distance between the outer slats should be about 2 meters:
Put the yellow acrylic plate with photogrammetric reference system on the floor between two bars:
4. Capturing the calibration video
Make sure that the camera settings have been adapted so that they are the same as if the drone was flying in the solar field (see drone settings in your document section in the app). You need to take a video to get the calibration data. You don´t need to fly the drone. It is necessary that you hold the drone in your hands above the cross in the middle and then move slowly around it.
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For each of the following steps, record an individual video |
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not flying (too much vibration)
not hand-held (Too much shaking)
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The drone must stand still and must not move at all. Grab a short video, a few seconds are enough. With this, we will be able to create a look up table in our system to know which pixels in the IR range correspond to the one in the visual video.
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