To effectively use the Bad Elf Flex Mini, the initial step is to configure the setup correctly. This involves setting the camera offset between the antenna and the mobile device's camera. This offset, whether measured automatically by PIX4Dcatch (SPC+) or manually by the user, is crucial for accurately computing locations captured by Pix4D-adapted RTK devices, ensuring precise measurements for scans or ground control points (GCPs).
IN THIS ARTICLE
Mount the Pix4D-adapted Bad Elf Flex Mini rover to the Device
Smartphone model
Camera Offset Measurements
How to Manually Measure the Camera Offset
Measure the X and Y axis
Measure the Z axis
Enter the Camera Offset Values
Mounting the Bad Elf Flex Mini RTK rover to the device
The Bad Elf Flex Mini is a GNSS RTK receiver that allows PIX4Dcatch to geolocate the images acquired by your mobile device with centimeter accuracy. The Bad Elf Flex Mini RTK rover can be coupled with mobile phones (iOS) using the SP connectors (cases or clamps) provided by SP Connect.
Note: The SP connectors can be obtained when purchasing the Bad Elf Flex Mini RTK Rover. They can also be purchased directly from SP-Connect and most electronic, bicycle, and motorcycle shops. When mounting for the first time, refer to the manufacturer's instructions for further details.
Smartphone model
Important: If the Bad Elf Flex Mini is not mounted with an SP-connect case, then offset values need to be measured manually, as described below. In PIX4Dcatch, there is an option to overwrite the autodetected values with the manually measured ones.
Camera Offset Measurements
When initiating the connection to the Bad Elf Flex Mini, the dialog RTK Device Settings opens. The section Camera Offset allows the user to set the X, Y, and Z offset values properly. The available options depend on the combination of the Bad Elf Flex Mini RTK device, the mobile device, and the device case. The following options are available:
- Left
- Right
- Custom
The Left & right options are only available if the combination of the Bad Elf Flex Mini RTK device version, the mobile device, and the device case is known. The option Custom is always available and intended to be used for universal cases. This option requires measuring the camera offsets manually and setting them in PIX4Dcatch. The camera offset value selection is saved for the next measurements, and modifications are only needed if the setup changes.
How to Manually Measure the Camera Offset
.png?width=600&height=464&name=badelf_mini_portrait%20(1).png)
Mount the device to the Bad Elf Flex Mini using the appropriate SP-connect case.
Place the device in portrait mode and the display to the front. Note the orientation of the X, Y, and Z axes and how they relate to the point of origin on the antenna to measure from. The point of origin resides in the middle of the screw mount at the base of the antenna. For devices with multiple camera lenses, it will also be necessary to determine which lens to measure from.
Tip: If the correct camera lens is unknown, start PIX4Dcatch and place an object in front of each lens. The blocked lens is the one to measure from.
Measure the X and Y axes
To measure the X-axis offset, measure the X-axis on the vertical axis from the middle of the antenna to the point where it intersects the Y-axis. Then, measure the distance from the camera lens to the center of the antenna.
Measure the Z axis
Measure the depth from the center of the handle to the center of the lens for the Z-axis offset.
Enter the camera offset values
With the camera offsets properly measured and recorded, they can be included in the appropriate Camera Offset Values field of the RTK Device Settings dialog. Depending on the device's geographical region, centimeters or inches will be the displayed measurement unit.
.png?width=250&height=500&name=offset%20(2).png)
The camera offset is now properly set in the Camera Offset Values X, Y, Z fields. Continue with the RTK Device Settings dialog to complete the Bad Elf Flex Mini RTK connection to the device.