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This dialog lets you select the Coordinate Reference System (CRS) for the survey.
Filename
Select the CRS or PRJ file you want to use.
•The Default will be Local.crs.
•Examples: UTM Worldwide.crs, NAD 83 (2011).crs
To view information about a CRS or PRJ file in this dialog, use the Browse button to open the file. TPC displays it's information at the bottom of the dialog. You can also choose Open CRS Folder, then open any CRS or PRJ file from the folder.
Note: TPC organizes CRS and PRJ files in sub-folders. You may need to open a sub-folder to find the CRS or PRJ file you are looking for.
Note: You can visit http://www.spatialreference.org/ to find additional Coordinate Reference Systems.
Default Folder
By default, TPC stores CRS and PRJ files in the "C:\ProgramData\Traverse PC \TPC Desktop [version]\CoordainteReferenceSystems\" sub folder.
You can store your own CRS and PRJ files in this folder or store them elsewhere and access them with the Browse button explained below.
Sub-Folders
You are free to create sub-folders to organize your CRS and PRJ files.
Browse Default Folder
Opens the File Open dialog to TPC's default location for CRS and PRJ files. If you have selected a file from a location other than the default, this button returns you to the default location.
Browse
Opens the File Open dialog to the location determined by the current CRS.
If you have selected a CRS or PRJ file from a location other than the default location, TPC leaves the complete path in the filename (i.e. C:\Projections\NAD 83 Oregon South.prj). TPC then uses the included path to direct the file dialog where to open. If you have other CRS and PRJ files stored at this location, they will be available to you.
This is a great tool if you store shared CRS and PRJ files on a network file server or external drive or USB device.
Preview
Once you have selected a CRS or PRJ file, you can Preview it. TPC opens the file in your default word processor.
Zone
Select the corresponding zone. The zone data for each zone is stored in the TpcZone.dat file in the TPC program folder and can be edited in any text editor. The ZONE.DAT file is self documenting.
Note: If you select a PRJ file form the Filename pulldown, TPC removes the Zone pulldown from the dialog. This is because PRJ files define a single projection (Zone).
Ellipse
Choose this button to edit the ellipse parameters for your grid. If you are modifying the survey grid, these values are stored with the survey and used for all its grid geodetic computations. Any changes you make are also stored in TPC registry and will be used the next time you start a survey.
This can be set by the Ellipse record in a CRS or PRJ file.
Feet <=> Meters
If your survey is in Feet, specify whether you want to convert to meters using the International Foot (0.3048 M/FT) or the US Survey Foot (0.3048006096 M/FT).
This can be set by the SurveyUnits record in a CRS or PRJ file.
Geoid
The geoid group box lets you select a geoid to compute elevations from ellipse heights and visa versa.
Cache Survey Extents
By default, TPC access the geoid file each time it computes a geoid height for a location (coordinate or geodetic position). Actually, it access an area immediately around that location to compute a gradient used to interpolate the desired geodetic height. Call this the location buffer. TPC can compute additional locations within this location buffer without again accessing the geoid file.
If you have lots of points spread out over a large area, the location buffer will not be large enough and TPC will need to access the Geoid frequently, slowing down program operation.
The solution is to turn on [x] Cache Survey Extents. TPC will computed the extents of your survey, plus some additional distance, like 500 feet or meters, read that area one time from the geoid file and cache that data in memory. Now, any geoid height computation will happen in memory.
The Refresh button recomputes the survey extents and re-caches the geoid data for that area.
Browse Default Folder
TPC stores its own geoid files in the C:\ProgramData\Traverse PC\Geoids\ folder. You can access all of TPC's geoids with this button. When you select a geoid, it because the geoid used by the survey.
When TPC sees that you are using one of it's default geoid files, it removes the folder location C:\ProgramData\Traverse PC\Geoids\ and displays just the geoid filename in the Geoid group box.
Browse
If you have chosen to use your own geoid file, TPC displays that geoid file with it's full path in the Geoid group box. So for example, if the geoid you are using is on your office server mapped to the X: drive, your geoid path might be something like X:\Geoids\MyGeoid.pgm.
Selecting this Browse button will look at the path being displayed and access that path with the File Open dialog.
Install
Choose this button to access Traverse PC's Geoid Download web page https://traverse-pc.com/traverse-pc-land-surveying-software-support/tpc-geoid-downloads/. TPC lists the geoid models that it supports, with a download link for each.
To install a geoid model, click the download link and install it. TPC will install the geoids to the C:\ProgramData\Traverse PC\Geoids\ folder.
OK
Update the CRS of the survey.
Cancel
Return without updating the CRS.
Related Topics
Coordinate Transformations
CRS Files
Coordinate Reference Systems
Choosing a Coordinate Reference System
Editions
Premium, Professional
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