ON-SITE UAV CALIBRATION
The calibration tool allows you to easily calibrate the external magnetometer embedded into the GPS antenna. Calibration is important as it reduces measurement errors and improves navigational solutions.
Please note that on-site calibration does not remove or delete factory calibration parameters, it is simply added to the factory calibration.
To perform calibration, you must follow these steps:
At the bottom of the Calibration page, you will find:
The number of collected points, the percentage of maximum norm error before calibration (in red) and after calibration (in green).
You can also find the calibration parameters (scale factor, misalignment and bias errors) that are currently present in your SKYMATE (in the right-hand column), as well as the calculated calibration parameters (in the left-hand column).
The push button pushes calibration parameters into SKYMATE and it is disabled by default.
You will be able to push the calibration parameters into SKYMATE when the following two conditions are fulfilled:
First, the number of collected points must be equal or greater than 200 and, second, the collected points are well distributed over the space.
SkyControl has a tool to help you track the distribution of the collected points over the space. Click on the '2D Views' button in the right-top corner of the page.
Six circles are obtained. During data collection, the quadrants of the circles will gradually fill up in yellow color and will turn into green when a sufficient number of points is obtained. The second condition is fulfilled when all six circles in the 2D view completely turn into green.
Click on the "Clear Autopilot" button to reset the existing on-site calibration parameters
Start collecting measurements by rotating your UAS as follows:
Hold the aircraft in level position with SKYMATE x-axis pointing in the same direction as you. Make a 360 degrees around yourself.
Pitch down the aircraft for 90 degrees so that SKYMATE x-axis points downwards. Make a 360 degrees around yourself.
Pitch the aircraft another 90 degrees so that the aircraft is upside down and SKYMATE x-axis points in the opposite direction as yours. Make a 360 degrees around yourself.
Pitch the aircraft another 90 degrees so that SKYMATE x-axis points upwards. Make a 360 degrees around yourself.
Hold the aircraft in level position with SKYMATE x-axis pointing in the same direction as you. Roll the aircraft for 90 degrees to the right. Make a 360 degrees around yourself.
Hold the aircraft in level position with SKYMATE x-axis pointing in the same direction as you. Roll the aircraft for 90 degrees to the left. Make a 360 degrees around yourself.
Repeat the above steps until the two conditions are fulfilled.
These steps will fill the 2D circles in the order from left to right and from top to bottom.
During this step, the collected data will be displayed in red. If there are no errors, all the red points will lay on the reference sphere (in blue).
If this is not the case, the percentage of fitting error before calibration will indicate how far the collected data are from the reference sphere.
The scale factor, the misalignment and the bias errors will be calculated in real-time whenever a new measurement is collected.
Once the two conditions are fulfilled, the push button will be activated, click it to push calibration parameters to SKYMATE.
The calibrated data will be displayed in green.
At this point, you may judge the calibration quality by inspecting if the green points lay on the reference sphere or not and by comparing the fitting error percentage before and after calibration.
You will also be asked to disconnect and to reboot the autopilot.
Disconnect the battery and you are ready to fly.
For more in-depth information, please consult your SKYMATE user manual.