Understanding Point Types

The software supports two basic types of points:

Normal points are created when you import into your project any type of point data other than coordinate point data contained in a text file (for example, .csv) with "Unknown" or "Mapping" quality. You can also create normal points manually using the Create Point command.
A normal point includes one or more coordinate and/or observation nodes nested beneath it in Project Explorer that are used to compute the coordinate for the point. You can edit values for coordinate nodes, or change the coordinate quality level, in the Properties pane. These changes are reflected in the read-only coordinates displayed for the point in the Properties pane.
Read-only point coordinates are displayed in the Points Properties pane as shown here...
1. Grid Coordinate - A grid coordinate is a standard projected coordinate consisting of an easting, northing, and elevation in the zone and geoid model specified for the project's coordinate system. Grid coordinates may be adjusted, when required, using the Local Site Settings or Site Calibration command. The zone name and geoid model name are displayed in the Grid Coordinate section header.
2. Local Coordinate - A local coordinate consists of a latitude, longitude, and ellipsoidal height in the geodetic datum associated with the project's coordinate system zone. The parameters used to transform between global and local coordinates are displayed on the Datum transformation tab in Project Settings > Coordinate System. The parameters may be null when the global and local datum are the same. The local datum name is displayed in the Local Coordinate section header.
3. Global Coordinate - A global coordinate consists of a latitude, longitude, and ellipsoidal height in the global reference datum specified for the project's coordinate system. The global reference datum is used to express reference positions in the specified country. This ensures that VRS coordinates can be imported as global coordinates, while RTX coordinates are automatically converted from ITRF2014 at the measurement epoch to the global reference datum. The global reference datum name and global reference epoch are displayed in the Global Coordinate section header.
Notes:
- To make changes to the project's coordinate system, select Project Settings in the Quick Access Toolbar and select Coordinate System in the left pane. See Coordinate System Settings for additional instructions.
- When a site calibration has been performed or you are using ground coordinates in the project, the Grid Coordinate section label is replaced by Calibrated Coordinate or Ground Coordinate.
- A geoid model is optional in TBC. When no geoid is specified, the elevation of a grid coordinate is the same as the local ellipsoidal height. In this case, the grid coordinate will be defined using only the coordinate system zone.
- When “WGS 1984” is specified as the global reference datum in the project, time-dependent transformations are deactivated in TBC because the global reference datum is unknown. In this case, the label “WGS 1984” is still used for consistency with other software, but no reference epoch is provided.
A specialized type of normal survey point is an "as-staked" point. This is a point that was staked in the field based on a design specification. The as-staked point is typically imported into a project in a JobXML (.jxl) file along with its corresponding design point and computed delta values. Trimble Business Center flags any as-staked points whose horizontal and/or vertical deltas exceed the tolerances you specify in Project Settings. For more information, see View As-Staked Point Data.
Another specialized type of normal point is a "measure-to-surface" point, which is an imported point that includes a measurement to a specified surface. This enables you to, for example, easily compare topo shots to an original ground surface model, or measure the clearance from the top of a tunnel to the road surface. For more information, see View Measure-to-Surface Point Data.
Lightweight points arecreated only when you import a text file (for example, .csv) containing coordinate point data with "Unknown" or "Mapping" quality (for example, topographic points).
A lightweight point does not include coordinate nodes nested beneath it in Project Explorer. A non-editable coordinate is displayed for the point in the Properties pane.
Note the following concerning lightweight points:
- You can add an editable coordinate to a lightweight point by right-clicking the point in Project Explorer and selecting Add Coordinate. This changes the lightweight point to a normal point.
- If you import a text file with "Unknown" or "Mapping" coordinate quality into a project that already contains point data, duplicate points will be created for points in the text file (lightweight points) and points already in the project (normal points) that have the same ID (that is, points will not merge as expected). To avoid this problem, import the text file first to create the lightweight points in the project, then import the other point data. The lightweight points from the text file will merge with the normal points from the other point data to create normal non-duplicated points.