Issue:
New, no-distortion localized coordinate systems are being created which do not yet exist in Map 3D/Civil 3D. These are the steps to create a new coordinate system from the information contained in a PRJ file.
In this example, we will be creating a coordinate system for Franklin County, Ohio, based on the contents of this PRJ file:
PROJCS["Franklin",
GEOGCS["GCS_NAD_1983_2011",
DATUM["D_North_American_1983",
SPHEROID["GRS_1980",6378137.0,298.257222101]],
PRIMEM["Greenwich",0.0],
UNIT["Degree",0.0174532925199433]],
PROJECTION["Transverse_Mercator"],
PARAMETER["False_Easting",164041.666666],
PARAMETER["False_Northing",328083.333333],
PARAMETER["Central_Meridian",-83.10],
PARAMETER["Scale_Factor",1.000037],
PARAMETER["Latitude_Of_Origin",39.75],
UNIT["Foot_US",0.3048006096012192]]
Solution:
In AutoCAD Map 3D or Autodesk Civil 3D, select the Planning and Analysis Workspace. On the Map Setup tab, in the Coordinate System panel, select Create > Create Coordinate System to start the wizard.
1. Create coordinate system- Select Create a coordinate system definition
2. Specify starting point- Select Start with a coordinate system, then "next."
3. Specify coordinate system- Select Create a new coordinate system. Coordinate system type = Projected
a. Create coordinate system
Code: Specify a unique code for the new coordinate system.
Description: Enter a description of the new coordinate system.
Source: Enter the data source from which the values for this coordinate system were taken.
(Note: Description and Source can contain anything you want but cannot be left empty.)
Unit: Select the units to use for this coordinate system.
Categories: Select the category (or categories) in which this coordinate system will appear.
Referenced to: Select Geodetic, then "select." In the Coordinate System Library, highlight NAD83, then "select."
When all fields have been filled, click "next."
b. Specify projection
Select Transverse Mercator, then confirm by choosing "Yes."
Copy and Paste values from the PRJ file to the form as shown.
When all fields have been filled, click "next."
c. Specify common parameters
It is not necessary to add any information to this page, but for the best performance of the Online Maps, it is a good idea to limit the Useful Range. The latitude and longitude values show here are just outside of the limits of Franklin County. When complete, click "next."
4. Review coordinate system- Compare the values on this page with the PRJ file.
(Notes: GEOGCS will show "LL83". It is equivalent to "GCS_North_American_1983". Rounding is expected so some values will not precisely match.)
When complete, click "finish."
The new coordinate system is now ready for use by any version of AutoCAD Map 3D or Autodesk Civil 3D installed on the same computer.
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