Quick Guide for using Target Scans to tie a second Scan Position to a Scan Position registered by OCC/BS Registration
To tie an additional Scan Position to a Scan Position that was registered with the Occ/BS method, follow these steps.
Set at least three Targets where they are visible from both the current Occupation point and where you need to place the new Scan Position.
Perform Target Scans on the targets before moving the instrument from the Scan Position that will be registered with the Occupation/Backsight method.
Use a 0.00 Target Height for these Target Scans.
Move the scanner to the new scan location, create a New Station, and perform Target Scans on the targets.
Use a 0.00 Target Height for these Target Scans.
Perform any other scans that you need from this Scan Position.
We are now ready to take the field data into the ScanMaster office software.
Create a New Project
File/New(Left Click)
Enter Project Name in File Name field/Save
Import the Control Point file
File/Import
Browse to the location of the Control Point file that you will use for this project
Click the Open button to begin the import
The Import Text File dialogue will open
Click on the Header for each column of the text file to assign the proper aspect of the control point; for example, Point Name, X-Coordinate value, Y-Coordinate value, Z-Coordinate value
Continue until all headers are properly set, then click OK.
Next, import the .prj file for this project.
File/Import
Browse to the location of the .prj file that you will use for this project
Select .prj file and Open
This will open the Import .prj dialogue
Review the items to be imported. Uncheck any unwanted items. Click the Import button to begin the import.
In the Project Explorer, check the corresponding box of any item to view it in the Cube view (for this example, we will view the scan “int” from Scan Position “6bs8”).
The point cloud from that scan is now visible.
Check on a scan from a different Scan Position and we can see that the Scan Positions have not been registered.
Begin the Occupation and Backsight (OCC/BS) Registration process.
When the OCC/BS process is used in the GLS-1500 on-board software, ScanMaster automatically creates a Tie Point from the Target Scans during the prj file import process.
The TargetHeights are automatically entered as 0.00; we want to use the correct Rod Height that we used in the field.
So, we will delete all of the Tie Points that were automatically created.
Place the cursor over the Scan Position, right click, then click on Activate.
Place the cursor over the Tie Point in the Project Explorer, right click, then click on Delete
Once the Tie Point has been deleted, enter the correct Rod Height for that Target Scan.
Select the Target Scan by left clicking on it.
Once the Target Scan has been selected the properties will be displayed at the right of the screen. Upper arrow – Object Properties; Lower Arrow – Rod Height field.
Edit the Rod Height field with the correct value that was used in the field; in this example the field measure up was 4.69 US Feet.
Next, we will add the correct details for the Control Points for the Occupation and Backsight positions.
To do this, select the Scan Position by left clicking on it.
This will update the Object Properties with the details for this Scan Position.
In the Object Properties window, verify the Instrument Height value is correct (edit if necessary), update the Occupation (Control Point the scanner was over), Backsight-Global (Control Point the Backsight was over), and Backsight-Local (Tie Point for this Backsight) fields.
Yellow Arrow – Instrument Height
Blue Arrow - Occupation
Red Arrow – Backsight-Global
Green Arrow – Backsight-Local
These arrows were added as a visual aid. You will not see the arrows in ScanMaster.
Left Click on the Registration tab at the top of the display.
Select the Scan Position to be registered. Check the Occupation and Backsight bubble at the bottom of the screen
Then left click on the Right Arrow in the middle area of the screen.
A results message will appear. If the registration is successful, the Scan Positions will stay on the “Registered Scan Positions” side.
Left clicking the Default tab returns us to the Cube View of the scan data.
The Scan Positionis now properly registered based on the control points we used.
With the Scan Position registered, any points we create from this scan data will be properly referenced with coordinate values based on the control point coordinate system.
Create Tie Points from the Target Scans from the Scan Position that we just registered by Occ/BS method.
Place the cursor over the Target Scan, right click, then Create Tie Point.
Repeat this process for all the Target Scans from this Scan Position.
Create Points from the Tie Points that you just created.
To make it easier to select the correct object, turn off all the data except for the Tie Points. This will leave only the Tie Points visible.
Left click on the first Tie Point to select it; the Tie Point should turn yellow.
In the Main Menu, click on Create/Point then follow the instructions in the lower left corner of the screen;
CTRL + Left Click on the Tie Point to create a Point.
A point has now been created at the Tie Point location. This point will have coordinate values in the same coordinate system as your control point system.
To check this, click on the new point to select it.
Review the details in the Object Properties box at the left of the screen.
Repeat this process for all of the Tie Points.
We now have created new points with the correct georeferenced coordinates.
We will now work with the second Scan Position.
NOTE: Remember to Activate the Scan Position
Turn off all data from all the Scan Positions. This will help us to easily see the Tie Points we will create.
Create Tie Points from each of the Target Scans using the same process as above.
Create Tie Point Constraints from each of the Tie Points that you just created.
Left click on the Tie Point to select it; the Tie Point will turn yellow.
In the Main Menu, click on Create/Create Tie Point Constraint
The Create Tie Point Constraint dialogue will display. Click the OK button.
Repeat the process for all the Tie Points in this Scan Position.
We will now use the points that we created in the Occ/BS Scan Position to Georeference the Tie Point Constraints in the second Scan Position.
Left click on the Tie Point Constraint to select it.
The Object Properties window at the left of the screen will be updated with the property details of the selected Tie Point Constraint.
In the Object Properties box, use the drop down menu in the Georeference field to select the point that corresponds to this Tie Point Constraint.
Repeat this process for each of the Tie Point Constraints.
When all the Tie Point Constraints Georeference details have been updated we can Register this Scan Position.
Click on the Registration tab at the top of the screen.
Select the Scan Position that you have just set the Georeference details for, check the Tie Point Constraints bubble at the bottom center of the screen.
Click on the green, right arrow button in the middle of the screen.
A results message will appear. If the registration is successful, the Scan Position will stay on the “Registered Scan Positions” side.
Left clicking the Default tab returns us to the Cube View of the scan data.
The Scan Position is now properly registered based on the control points we used.