Supported Coordinate Reference Systems in 3D Mapping context

Orbit has the objective to support coordinate systems as they are described in the EPSG database by the OGP (International Association of Oil and Gas Producers).

Up to now Orbit supports any combination Geographic, Geocentric and Metric projected coordinate systems.
If it is your wish to use Feet projected coordinate system, please let us know. It is on our wishlist for a future update.

More information :

• It is strongly recommended to read first the documentation about Coordinate Reference Systems.
• If you would like to know more about coordinate systems go ahead with Coordinate Reference System in Theory.

Orbit supports any combination of mobile mapping data and any coordinate system on import. But be wise :

• The coordinate reference system should be part of the metadata of each resource.
• It is advised that all georeferenced resources are using the same CRS to avoid processing time of continuous coordinate transformation. If required convert CRS on import run.
• When converting the coordinate system of image positions apply the according adjustments on all orientation angles referring the coordinate system reference.

The coordinate systems of all runs in a project must be the same. Convert CRS on import run if required, see above.

More information, see Concepts of Mobile Mapping and UAS data in Orbit

Point measurements (XYZ coordinates) are expressed in the Map Coordinate System, see Coordinate Reference Systems.

• When using the Orbit desktop products the Map crs can be set from the MapCanavs Statusbar.
  
• When using the Orbit Web client it is the administrator who defines the Map and publication coordinate system.
• If no vertical CRS is set the Z of your mobile mapping data will be retained.

Distance, Length, Area or Volume measurements are expressed in metric units.

• The results are calculated in a local projection centered on the current view position.
  This intelligent technique gives the most accurate metric measure result at all time.
• Projected measure results are always displayed in meters.

More information, see 3D Measurements.

When saving 3D measurements as features to a Dataset or Inventory Theme, measured coordinates will be converted respecting the Dataset CRS and Coordinate Type (2D, 3D). Attribute Rules using a relative measure result (e.g. length, height difference, clearance, … ) will be saved as calculated, see above.
To review and modify Dataset Coordinate Type, see Dataset Structure.

• A measurement can only be saved to a dataset if the dataset CRS is defined.
• When saving measurements to a 2D dataset, XY will be saved and Z ignored (=0).
• When saving measurements to a 3D dataset and the vertical dataset CRS is not defined, the measured Z coordinate will be saved, see above.
• When saving measurements to a 3D dataset and the vertical dataset CRS is defined, the measured Z coordinate will be converted accordingly.

The Theme CRS is set on creation.
At import or export Theme coordinate transformation and/or re-projection are supported, see Manage Asset Inventory Themes

Working with multiple coordinate systems requires special attention.
Some simple rules to avoid issues on doing feature extracting from mobile mapping resources :

• Use the same coordinate system for all resources
• Avoid any intermediate coordinate transformation
• Extract features in the same coordinate system as the resource mobile mapping data
• Only convert coordinates at import or export Themes, see Manage Asset Inventory Themes.

Orbit advises to do your data production in the same coordinate system as your mobile mapping data. If required theme can be exported to any coordinate system. This workflow avoids coordinate transformation at time of production

If you would have any coordinate system related question, contact the Orbit Support team (support at orbitgt dot com).