/////Editing Survey Points

Editing Survey Points

posted by on August 07, 2017
As discussed, it takes many points to survey a piece of land—that’s hundreds or even thousands of individual measurements and hand-typed field codes. On nearly every project, there will be items that require editing. Once the data has been imported into Civil 3D, the field crew is off to its next job and the task of fixing things up will belong to you.

For several reasons, editing survey points is a bit different from editing “regular” points, properly referred to as COGO points. One reason is that survey points are considered “sacred” and are not typically moved or modified in any way without considerable thought and/or the supervision of a surveyor. The second reason, related to the first, is that Civil 3D uses a separate survey database system to store points. The points in the drawing are essentially locked and cannot be changed unless the information in the survey database changes. With this system, a surveyor can send out the drawing file without sharing the survey database that goes with it. When the points in the drawing are separated from the survey database, they become locked and cannot be easily modified. In this way, the survey database gives control of the points to the person who created them.

A Note about Units

Throughout this chapter, you'll notice that two values are provided for units of measurement. The first value is provided for the imperial system that is used in the United States, and the second value, in parentheses, is provided for the metric system that is used in many other countries. These values most often represent imperial feet and metric meters. It is important to note that, generally, only the numeric values are entered in the software, not terms like feet or meters. Also, you should know that the two numbers provided are not necessarily equal. In most cases, they are similar values that are rounded to work efficiently in their respective measurement systems.
To edit a survey point to correct an error in field coding, follow these steps:
  1. Open the drawing named Edit Survey Points.dwg or (Edit Survey Points.dwg (METRIC)) located in the Exercise_03 class data folder.If a survey database is open, right-click it and select Close Survey Database.
  2. Locate and zoom in to the red point along the west treeline, as shown in Figure.
    Editing Survey Points
    An error has caused this point to display incorrectly.
  3. Open the Properties window, and then select the red point. Note that there is a typo in the raw description. It should say TR 12 PINE (TR 300 PINE) instead of TTR 12 PINE (TTR 300 PINE). You cannot edit the raw description here because the data is actually stored in the survey database.
  4. With the point still selected, click Survey Point Properties on the ribbon. A dialog box will open, informing you that you must open a survey database.
  5. Click OK to dismiss the dialog box. Then right-click the Essentials 4 survey database on the Survey tab and select Open for edit.
    Tips :The Essentials 4 database is the result of correctly completing the previous exercise. This database is provided to ensure that you start the current exercise with the correct version.
  6. With the red point still selected, click Survey Point Properties on the ribbon.
  7. Edit the description to say TR 12 PINE (TR 300 PINE) and click OK.
  8. Press Enter to end the command. You will then be prompted to update linework in the drawing. Answer No, since the change you made does not affect linework.
    Tips :The survey database is needed to edit the points. This is how the points are kept safe when the drawing is shared outside the survey office.
  9. Click the red point, right-click, and select Apply Description Keys. The effect of the description key will put the point on the correct layer, change its marker to a tree symbol, and provide a label indicating that it is a 12" (300mm) PINE.

Survey Points vs. COGO Points

As previously mentioned, there are two types of points: COGO points and survey points. How can you tell the difference? Here are a few characteristics of each to help you distinguish between the two:

Survey Point Characteristics
  • Only survey points are displayed on the Survey tab (COGO points are not).
  • Survey points are displayed on both the Prospector and the Survey tabs.
  • Survey points have an icon next to them that looks like a survey target (an hourglass inside of a box overlaid on crosshairs).
  • Survey points cannot be moved.
  • Survey points cannot be edited in the Properties window.

COGO Point Characteristics
  • COGO points are not displayed on the Survey tab.
  • COGO points have an icon next to them that looks like a circle overlaid on crosshairs.
  • COGO points can be moved, even with the Autodesk® AutoCAD® software move command.
  • COGO points can be edited in the Properties window.
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