Hi all,
When we place an active point in Bentley Map, we we all know, we can provide the data points to position the active point. So, what is the coordinate system we can use to provide these coordinates in? can it be geographic (Lat/Long) or our projected coordinate system? I read in the help documentation that we can use absolute coordinates also. So, can anybody please shed some light on this please? Appreciate your help.
Thanks in advance,
Kiran
Coordinate Systems in MicroStation are available from a Library. It is up to you to choose the appropriate coordinate system for the area and details that you are mapping.
MicroStation uses the geographic coordinate system library to map the three-dimensional surface of the earth to a two-dimensional surface, the design plane. So whether you choose a Geographic coordinate system (unprojected, L/L), or a Projected (ft/m) system, MicroStation positions the data in the correct location for you.
The following papers may be helpful in understanding the interaction between the coordinate systems, projections, and data. You should also use the Running Coordinates/ACS Position settings to control coordinate system input & readout:
- U.S. Coordinate Systems in MicroStation V8i and Bentley Map V8i
- Understanding Mapping Reference Frames for Engineering Projects - Grid to Ground
- Convert Local Coordinate Systems to Standard Coordinate Systems
- FAQ : Coordinate System Workflows Within Bentley Map V8i Releases
Don't confuse "coordinates" with "coordinate system". As you have said, your data is located at the coordinates of the SRID defined in the Oracle table. When a map is based on horizontal survey control points, the map will be drawn in the correct location on the design plane whether the DGN file has a coordinate system defined or not.
You can use the MicroStation Geographic Coordinate System tools to map the data in any map projection that you desire (3414 or something else). Internal calculations automatically 'reproject' the data to/from one coordinate system to another. This applies to References and Images as-well, provided they also have an assigned coordinate system.
If you are having trouble, or question whether the data is being placed in the correct position, use the Running Coordinates tools to verify their location. In the example shown here, the coordinates display correctly when the DGN file is set to two different Coordinate Systems: