Creating ASCII XYZ Files for GEOPAK Chains

This is the procedure the designer should use when asked to provide an ASCII file with Station/XYZ data for even increments along a GEOPAK chain and/or for the transit points (PC, PT, TS,SC, etc.) for a GEOPAK chain. Currently this is not part of the standard construction information that is provided to the Project Engineer or the contractor, but more and more frequently this information is being requested.

In order to do this procedure you need:

  1. The GPK file for the job.
  2. COGO name of the centerline chain.
  3. COGO name of the profile associated with the centerline chain.
  4. A large continuous block of unused COGO point numbers in the GPK file.

The following example assumes that you have been requested to supply Station/XYZ for both even increments and control points for chain A. The profile name is A and the GEOPAK job number is 000. Listing all point in the gpk file indicates that point numbers above 7000 have not been used.


1.  Store COGO points at even increments along the centerline chain.

Get into GEOPAK COGO and bring up the Locate Points Along Element dialog box (shown below right) by selecting Tools > Locate > Along Element from the COGO box pulldown menus. Set up the dialog as outlined below.
  1. Element.  Select the Chain option
  2. Locate Point.  First COGO point number to use for stored points. (Before picking a beginning point number be sure to check the COGO point numbers that are already used; this procedure requires a large block of point numbers and it will overwrite existing point numbers if you're not careful.)
  3. Inc Pt# By.  Increment to use for point numbers. For the example shown the first point will be 7000, the second 7001, etc.
  4. Chain.  Select the centerline chain name from the pulldown list.
  5. Locate at Even Stations. Check this box to force points to even stations.
  6. Select Distance option and
  7. key in the spacing along the chain for the points.
  8. Offset should not be checked.
  9. If you want points along the entire chain, then don't check the Station Range checkbox. If you want points for only a portion of the chain then check the box and fill in the From/To stations.
  10. Click on the Locate button to create and store points along the chain.
Locate Points along Element
  1. The COGO output window will display a list of all the points that are created and stored (see example at right). Scroll down to the end of the list of newly created points in the COGO window and note the last point number; you'll need to know this for step #2.
    (Notice that the points have no elevations assigned to then yet, only Station and NE coordinates.)
Coordinate Geometry
2.  Store COGO points at control points along the centerline chain.

Bring up the Equate Points dialog box (shown below right) by selecting Element > Point > Equate from the COGO box pulldown menus. Set up the dialog as outlined below.
  1. Equate From.  Select the Chains option .
    (Note: The appearance of the dialog will change dramatically depending on which option is chosen, so it may not initially appear as shown.)
  2. Beginning Point Name. Check the COGO output window to determine the last point number created in step #1 above. Key in the next point number in this field.
  3. Chain.  Select the centerline chain name from the pulldown list.
  4. The Hide/Show Options button controls whether the bottom portion (Control Point Options) of the dialog box is displayed. If the Control Point Options section isn't displayed then click on the button to make it appear.
    The option buttons in the Control Point Options section are used to control which of the key points are stored for each curve and spiral in the chain.
  5. Curves section.  Each button has five options (PC, PT, PI, CC, None). For most cases the user will want points at the PC and PT of each curve as shown in the example dialog. Set the remaining buttons to None.
  6. Spirals section. Each button has four options (TS/SC, SC/ST, PIS, None). For most cases the user will want the points at the TS/CS and SC/ST points as shown in the example dialog. Set the remaining buttons to None. If the chain has no spirals this section is ignored.
  7. If the chain has spirals then check Do not duplicate Spiral/Curve controls. This prevents storing duplicate points where the spirals connect to the curves.
  8. Click on the Apply button to store COGO points at the curve/spiral control points.
Point Equate
  1. The COGO output window will display a list of all the points that are created and stored (see example at right). Scroll down to the end of the list of newly created points in the COGO window and note the last point number; you'll need to know this for step #3.
    (Notice that the points have no elevations assigned to then yet, only Station and NE coordinates.)
Coordinate Geopmetry
3.   Assign elevations to the previously defined points.

Bring up the Locate Elevation by Profile Station dialog box (shown below right) by selecting Tools > Locate > Locate Elevations by Profile from the COGO box pulldown menus. Set up the dialog as outlined below.
  1. Point Range.  Key in the range of point numbers created in steps #1 and #2.
  2. Profile.  Select the profile associated with the centerline chain from the pulldow list.
  3. Chain.  Select the centerline chain name from the pulldown list.
  4. Constant +/-.  Set to 0.00.
  5. Click on the Apply button to assign elevations to all the points created in steps #1 and #2
  6. The COGO output window will display a list of all the points and the elevations assigned to them (as shown in the example below).
ocate Elev Coordinate Geometry
4.  Create an ASCII file with the Station/XYZ point data.

This step should be done using COGO key-in commands:
  1. Key in clear to empty the COGO output buffer.
  2. Key in print point 7000-7321 (your point range will obviously be different). A list of all the points similar to the example shown below should appear in the COGO output window.
  3. Key in out filename (where filename is any five or fewer characters) to write the list of points to an ASCII file. The actual name of the file on your hard disk will be filenameXXX.oYY, where XXX is the job number and YY is the operator code.
Create an ASCII file
5.  Edit and sort the ASCII file.
This final step of the procedure requires you to use the column editing features of UltraEdit.
  1. Open UltraEdit and bring in the ASCII file created in step #4. The first few lines of the ASCII file should be similar to what's shown in the example shown below.
  2. Delete out the "header" (shown highlighted in the example) at the top of the ASCII file. You'll need to remember which column is which, so write it down.
  3. Switch UltraEdit to Column Mode. (Column > Column Mode from the pulldown menus.)
  4. Delete the entire Point Number column.
  5. Cut and Paste the entire Station column to make it the first column in the file.
  6. Switch UltraEdit out of Column Mode. (Column > Column Mode again.)
Edit and sort the ASCII file
  1. Set up for sorting the ASCII file by station range. File > Sort > Advanced Sort/Options from the pulldown menus to bring up the dialog shown at right. Set up the dialog as shown.
  2. Move the cursor to the column containing the first digit of the point stations (probably column 1 if you did step #5e correctly).
  3. Double check to be sure you have everything set up correctly -- UNDO will not undo a bad sort operation.
  4. Click on the Sort button in the upper right corner of the dialog to initiate the sort.
  5. If the sort operation was done correctly you should see odd stations (for the PCs, PTs, etc.) sorted into the even station points as shown in the example below. Notice the begin point for the chain (1+234.567) is now the first first point in the file and that a PC station (1+334.567) is between the even stations 1+330 and 1+340, etc.
  6. Save the ASCII file. This is the final product the surveyors need to download to their data collectors.
Sort Ultra Edit