Importing Matching Points

When an imported point matches an existing survey point, TPC has to decide what to do. It can create a new (imported) point with a unique point label or update the existing survey point with the imported data. This help topics describes the decisions that TPC makes automatically when it finds a match and which ones you control by the option you select.

For the discussion below

1. Importing a point label and position that do NOT match an existing survey point (Automatic)

TPC creates a new survey point.

The imported data determines the position of the new point and any observations that might be used to recompute the position. The new point also gets its point description and attributes from the imported data.

TPC keeps track of how this new point was imported and sets the new point's origin acoordingly.

2. Importing a point label and position that match an existing survey point (Automatic)

TPC assumes that they are both referencing the existing survey point, and discards the imported point position and retains the existing point's position.

In the details, TPC displays Found existing survey point 100 (matching label and position)  Keeping existing survey point

This allows you to export parts of an existing survey to your data collector, collect additional field data, then import the entire data file back into TPC without creating unwanted duplicate points.

3. Importing a point label that match an existing survey point label, but the positions don't match (User Option)

TPC determines what do do based on wether the existing point is protected and the user's matching point setting from the Settings dialog.

a. Create a new point

TPC creates a new survey point.

The imported data determines the position of the new point and any observations that might be used to recompute the position. The new point also gets its point description and attributes from the imported data.

TPC keeps track of how this new point was imported and sets the new point's origin acoordingly.

After the import is finished, TPC relabels these points so they have unique point labels.

b. Use the existing point, and don't update it

If the imported data is a position, TPC assumes the intended imported point is the existing survey point, so it discards the position data for the imported point and uses the existing survey point instead.

In the details, TPC displays Found existing survey point [label] (matching label) Keeping existing survey point

The existing survey point is not changed.

If the imported data contains raw data (distance, direction, angles, etc), TPC adds an observation record for the existing point if the improted data contains raw data (distance, angle, direction, etc.). This information can be used in a Least Squares adjustment.

In the details, TPC displays Found existing survey point [label] (matching label) Adding redundant observation to existing survey point

The existing survey point is not changed.

c. Use the existing point, but update it

If the existing survey point is protected, TPC creates a new survey point.

In the details, TPC displays Can't update protected point [label]

Use point protection in conjuction with this option to updated just the survey points you want to update with the imported data.

If the existing survey point is NOT protected and the imported data is a position, TPC assumes the intended imported point is the existing survey point and updates it's position, description and attributes.

In the details, TPC displays

Found existing survey point [label] (matching label)

  Updating position from [old] to [new]

  Updating description from [old] to [new]

  Updating attributes from [old] to [new]

If the existing survey point is NOT protected and the imported data contains raw data (distance, direction, angles, etc), TPC adds the appropriate FS or SS record to the traverse, which may update the position of the existing survey point when the traverse is computed.

In the details, TPC displays Found existing survey point [label] (matching label) Adding raw data with may recompute existing survey point

Staked Point Exception

When importing raw data (distance, direction, angles, etc.) to an existing staked point with the @ symbol in the point label, TPC always just adds a new traverse point to the existing staked point. This lets you check a staked point any number of times without creating new points each time.

Updating Descriptions and Attributes

If you select the option Use the existing point, but update it, TPC appends the imported point description and attributes to the existing survey point, if they don't match. TPC tries to identify the unique part of the imported description and attributes and append them to the existing point.

Example: If the imported description for point 100 is FND 5/8" RBR and the description for the existing point 100 is blank, TPC will update the description of the existing survey point to FND 5/8" RBR.

Example: If the imported description for point 100 is 5/8" RBR YPC44138 FND and the description for the existing point 100 is 5/8" RBR YPC44138, TPC will update the description of the existing survey point to 5/8" RBR YPC44138 FND. where 5/8" RBR YPC44138 is the original description and FND is the unique part of the imported description which gets appended to the original descriptions.

Geodetics vs Coordinates

When it comes to deciding how to handle matching point labels and positions, TPC does not distinguish between coodinates and geodetic positions when comparing the points.

Exmaple: If you import point 100 with a geodetic position and TPC finds an existing point 100 with coordinate preference (its geodetic position was computed from the coordinates). TPC will compare the imported geodetic position with the geodetic position for the existing point 100 and preform the operations outlined above.

Related Topics

Import Settings
Report View
Message View

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