Coordinate Systems

Summary

Coordinate systems control how SDX-Cloud localizes project data and links it to the correct real-world position. In Data Projects and System Projects, the setup differs, so review the selected source and target systems carefully before you create the project.

Introduction

In SDX-Cloud, the coordinate system affects the absolute position and precision of the project. The setup can depend on the project owner, the construction site, and, in System Projects, the correction data service that is used. Data Projects focus on selecting predefined source and target systems, while System Projects focus on localizing the project with either a calibration file (LOK file) or an EPSG and height system combination.

Prerequisites

• You know whether you are creating a Data Project or a System Project.
• You have the correct coordinate reference information for the project site, including the required EPSG and height system details when applicable.
• You know which target system should be used for the construction site.
• For System Projects, you know whether you need a calibration file (LOK file) or an EPSG and height system setup.
• If you are unsure which coordinate system to use, contact Sodex Support before you create the project.

Step-by-step instructions

1. Define coordinate systems in Data Projects

1. Select the origin system that should be used as the global reference system for the project data.
2. Select the target system that should be used as the local Cartesian system for the construction site.
3. Confirm the EPSG code for each selected system so the configuration matches the intended reference systems.
4. Select the required vertical reference system from the available predefined height systems.
5. Wait for SDX-Cloud to validate the selected combination before you finalize the project.

Expected result: The selected source, target, and height systems form a valid configuration for the Data Project.

2. Define coordinate systems in System Projects

1. Define the target system based on the project location.
2. Decide whether the project should be localized with a calibration file (LOK file) or with an EPSG code and height system.
3. If you use an EPSG code and height system, select the required height reference such as an ellipsoidal or geoid-based setup, or apply the required offset or inclined plane configuration.
4. If the required geoid model is not available, contact Sodex Support or use the required offset or inclined plane method.
5. If the required EPSG code is not listed, search for and select the correct code before you continue.

Expected result: The System Project is configured with the correct target system and vertical reference setup.

3. Avoid datum-shift pitfalls

1. Compare whether a datum shift is applied in both the source and target coordinate systems.
2. If one system applies a datum shift and the other one does not, expect an offset in the transformed coordinates.
3. Review combinations such as WGS84 → ETRS89 carefully because this transformation can apply a datum shift.
4. If you want to stay in the same reference frame, combinations such as ETRS89 → ETRS89 or WGS84 → WGS84 are usually the safer choice.
5. If you are unsure which combination is correct, contact Sodex Support before creating the project.

4. Validate the setup before creating the project

1. Review the selected origin, target, and height systems one more time.
2. Make sure the selected systems match the project location and project requirements.
3. In Data Projects, resolve any invalid combination before you continue.
4. In System Projects, confirm that the required geoid model or localization method is available.
5. Create the project only after the configuration is verified.

Expected result: The project is created with the intended coordinate system and can be localized correctly.

Limits and notes

• The coordinate system cannot be changed after project creation.
• In Data Projects, SDX-Cloud validates the selected combination before project creation.
• In System Projects, the target system is based on the project location.
• If a required geoid model is missing, contact Sodex Support.
• If an EPSG code is not listed, search for and select the correct one.
• If you are unsure about the correct coordinate system, contact Sodex Support before continuing.

Related articles

• Article: SDX-Cloud: Overview
• Article: Ground Control Points in SDX-Cloud
• Article: Setup Ground Control Points to enhance your project's accuracy