Getting Started

Mount and configure a PIX4D adapted RTK device - Emlid


To effectively use an Pix4D-adapted RTK device with a mobile device, the initial step is configuring 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).

Mount the Pix4D-adapted Emlid RTK rover to the Device

The Pix4D-adapted Emlid is a GNSS RTK receiver that allows PIX4Dcatch to geolocate the images acquired by your mobile device with centimeter accuracy. The Pix4D-adapted Emlid 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 Pix4D-adapted Emlid RTK rover. They can also be purchased directly from SP Connect and most electronic, bicycle, and motorcycle shops. Refer to the manufacturer's instructions for further details when mounting for the first time.
If the mobile device does not have a custom case available (e.g. Android phones), the universal clamp can be used.
Important: After mounting the Pix4D-adapted Emlid RTK rover to the mobile device, please check if the camera offset has been automatically calculated for you. If your mount is not available in this list, you need to measure the camera offset manually.

Smartphone model

First, insert the phone into its compatible SP-connect case. Then, mount the case to the device by following the instructions provided with the SP-connect case.

Important: Ensure proper orientation of the mobile device after mounting it to the Pix4D-adapted Emlid RTK rover with the antenna pointing up.
Device type
Devices with a Known Camera Offset

This list contains the combinations of mobile devices (phones and tablets) with the Pix4D-adapted RTK devices where the camera offsets are already measured. PIX4Dcatch will automatically fill in the X, Y, Z fields with the correct camera offset values.


Smartphone model
iPhone 15 Pro Max
iPhone 15 Pro
iPhone 14 Pro Max
iPhone 14 Pro
iPhone 13 Pro Max
iPhone 13 Pro
iPhone 12 Pro Max
iPhone 12 Pro
iPhone 11 Pro Max
iPhone 11 Pro
iPhone XR
Important: If the Pix4D-adapted RTK devices 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 Pix4D-adapted RTK devices, the dialog RTK Device Settings opens. The section Camera Offset allows the user to set the X, Y, Z offset values properly. The available options depend on the combination of the Pix4D-adapted Emlid RTK device version, the mobile device and the device case. The following options are available: SPC+ and Custom.

The option SPC+ is only available if the combination of the Pix4D-adapted Emlid RTK device version, the mobile device and the device case are known. The option Custom is always available and intended to be used by universal or specific 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

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Mount the device to the Pix4D-adapted RTK devices using the appropriate SP-connect case. Phone cases can be purchased separately from the SP-connect website. The SP-connect universal phone mount can be used if the specific model is unavailable. SP-connect cases are also available in most bicycle and motorcycle shops.

Place the device in landscape mode and the display to the front. Notate 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. It will also be necessary to determine which lens to measure from for devices with multiple camera lenses.


Tip: If you don't know which camera lens to measure from, start PIX4Dcatch and then place something in front of each camera lens. The lens blocked is the appropriate lens to measure from.

Measure the X and Y axis

To measure the X-axis offset, simply 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.

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 Pix4D-adapted Emlid RTK connection to the device.