A coordinate reference system provides information and parameters that ensure coordinates are correctly displayed on a map. Depending on your configuration, you will need to select the appropriate input and output coordinate reference systems and the geoid when applicable.
Tip: When discussing coordinate reference systems, it is highly recommended to use EPSG codes. The coordinate reference system can easily and unambiguously identify with an EPSG code. Using only the names can be confusing, and they can often be misinterpreted. Check the http://epsg.org/ website to search for the desired coordinate reference system.
Refer to Coordinate reference systems and 2D projections for more information.
IN THIS ARTICLE
NTRIP coordinate reference system
Select the NTRIP coordinate reference system using the Pix4D supported RTK device
Output coordinate reference system
Select the output coordinate reference system when uploading to PIX4Dcloud
GCP coordinate reference system information
NTRIP coordinate reference system
When using an RTK-enabled device, the NTRIP coordinate reference system is the system used by the NTRIP service to broadcast corrections in.
Note: For non-RTK captures, PIX4Dcatch automatically sets the horizontal coordinate reference system to WGS84 (EPSG:4326) and the vertical coordinate reference system to EGM96 height (EPSG:5773).
Select the NTRIP coordinate reference system using a Pix4D suported RTK device
- Tap the signal indicator
then select RTK via Bluetooth.
- In the RTK Device Settings dialog:
- Select the Pix4D supported RTK device under Available Bluetooth Devices.
- Enter the NTRIP details, then tap Connect:
- Hostname / IP
- Port Number
- Username
- Password
- When the connection is established, under Choose mountpoint, select the preferred mountpoint.
- Tap
to select the NTRIP coordinate reference system.
Important: Select the coordinate reference system used by the NTRIP service to broadcast its corrections as the NTRIP Coordinate System. If uncertain, contact the NTRIP service provider for this information.
We have identified several coordinate reference systems commonly used for broadcasting NTRIP corrections from various regions.
Country or region
Coordinate reference system
Europe
ETRS 89 (EPSG:4258)
United States
NAD83(2011) (EPSG:6318)
Japan
JGD2011 (EPSG:6668)
Singapore
SVY21 (EPSG:4757)
- Tap Save.
Output coordinate reference system
The output coordinate reference system is used to reference the reconstruction after processing. It does not need to be the same as the input coordinate reference system or the GCP coordinate reference system.
Note: When uploading a project to PIX4Dcloud/PIX4Dcloud Advanced with RTK image geolocation, it is possible to manually select the horizontal and vertical coordinate reference systems and the geoid (when available). It is also possible to select the output coordinate system when an exported project is imported into PIX4Dmatic, PIX4Dmapper, or another third-party software.
Refer to How to Use Coordinate Systems to select the coordinate reference systems in PIX4Dmatic
Refer to Select Output Coordinate System to select the output CRS in PIX4Dmapper
Select the output coordinate reference system when uploading to PIX4Dcloud / PIX4Dcloud Advanced (RTK enabled device)
1. Tap Upload 
2. Tap Output coordinate system.
3. Tap Manual to select the horizontal and vertical coordinate reference system.
Note: Auto Detected sets the horizontal coordinate reference system in the UTM zone corresponding to the location of the project. e.g. the horizontal coordinate reference system to WGS84 / UTM zone 32N (EPSG:32632) and the vertical coordinate reference system to EGM96 height (EPSG:5773), for Lausanne, Switzerland.
To manually select the output coordinate reference system:
- Tap
to select the horizontal coordinate reference system:
- In the Horizontal coordinate reference system dialog, search or copy-paste:
- The name
or - The EPSG code of the coordinate system.
- The name
- In the Horizontal coordinate reference system dialog, search or copy-paste:
- Tap
to select the vertical coordinate reference system:
- In the Vertical coordinate reference system dialog, search or copy-paste:
- The name
or - The EPSG code of the coordinate system.
- The name
- In the Vertical coordinate reference system dialog, search or copy-paste:
- (Optional) Tap
to select a geoid: If the selected vertical coordinate system supports geoids and the geoid model is available in the PIX4D database, select the geoid model in the drop-down list. - Tap Done.
Important: Ensure the correct vertical coordinate system and/or geoid is selected.
- Tap Upload.
Refer to How to use vertical coordinate systems and geoids - PIX4Dmatic for more detailed information.
Note: For non-RTK captures, PIX4Dcatch automatically sets the output coordinate reference system in the autodetected UTM zone corresponding to the location of the project, e.g. the horizontal coordinate reference system to WGS84 / UTM zone 32N (EPSG:32632) and the vertical coordinate reference system to EGM96 height (EPSG:5773), for Lausanne, Switzerland.
GCP coordinate reference system information
When collecting GCPs it is possible to select the coordinate reference system to export the GCPs in.
Note: When creating a new GCP collection PIX4Dcatch will prefill the horizontal and vertical fields depending on the current region and configuration information.
- With Pix4D supported RTK device:
- Horizontal: Depends on the NTRIP CRS entered. e.g. ETRS89 (EPSG:4258), NAD83(2011) (EPSG:6318), JGD2011 (EPSG:6668), etc.
- Vertical: Ellipsoidal height
- With GPS:
- Horizontal: WGS 84 (EPSG:4326)
- Vertical: EGM 96
Important: The same coordinate reference system used to collect GCPs must be selected when importing the GCP files into PIX4Dmatic, PIX4Dmapper, or any other third-party software.
Refer to How to import GCPs to PIX4Dmatic, or How to add / import GCPs in the GCP/MTP Manager (PIX4Dmapper) for more information.