Understanding Coordinate Reference System datum modes (Beta)

Note: This feature is still in beta.  Contact support@pointerra.com if you would like access to this feature.

As of May 2024, there are two datum modes that can be used when spatial referencing data in Pointerra (the default mode is currently configured on a per-account basis).

Fixed datum mode

This is the datum mode that has always existed. All data processed prior to May 2024, or any new data processed using the existing mode is now referred to as using fixed datum mode. In fixed datum mode, it is assumed that all data within a project is referenced to the same datum (in the vast majority of projects, this will be the case).  Data using different datums can be combined in a project, however as no datum shift is applied, these datasets may not align accurately.

Advanced datum mode (new)

The new advanced datum mode provides complete support for datum shifts as required (both horizontal and vertical) across all areas of the platform. This allows for datasets within a project to be referenced to different datums and still align correctly.

The primary enhancements that are enabled by using the new advanced datum mode are:

• Full support for datum shifting when performing coordinate transforms. This enables datasets using different datums to be combined accurately in the same project.
• A greater range of pipeline options to perform complex transforms, resulting in coordinate transforms that may be more accurate in some cases.
• Support for modern spatial referencing concepts, such as datum epochs.
• Support for a wide range of vertical coordinate reference systems.
• Support for additional CRS definition methods such as authority codes, Well-known Text (WKT) and compound coordinate reference systems.
• A larger and updated database of coordinate reference systems to choose from.
• Better support for local grids and other specialised definitions.

Advanced datum mode also enables additional platform features such as:

• Point clouds can now be merged and align correctly even if the source point clouds are referenced to different datums.
• Projects can contain datasets (e.g. vector data, CAD data) where the datasets are referenced to different datums than the point cloud/project.
• Projects can display coordinates in any coordinate reference system - including CRS with datums that are not the same as the data within the project.
• Data can be exported into coordinate reference systems that use a different datum (both horizontal and vertical).
• Vertical referencing now supports a wide range of specific datums (e.g. AHD, NAVD88), rather than only ellipsoid/orthometric.

What are the impacts of the change for existing customers?

Due to the way that most data within the platform is referenced/processed to a common global coordinate system to allow visualisation of data in different coordinate systems (but until now, not necessarily different datums), data processed using the new advanced datum mode cannot be used with data processed in the fixed datum mode. To do this will require reprocessing of the existing data. For most customers this is unlikely to be an issue, unless there is a specific need to merge together older data with data processed in the advanced datum mode.

For most existing customers, there may be no need to move to the new advanced datum mode if your projects typically have all data referenced to the same datum. The overhead of needing to reprocess existing data would not be worth the benefit. For further assistance or more detailed information on transitioning to the new datum mode, please contact our support team.