Power line detection

Main interface

The power line detection tool has a few options to manage any power lines in the item list - see their description here:

There are also a few options at the bottom of the window:

• Save: Saves the selected power lines to a PWL or TXT format.
• Load: Loads a PWL or TXT file to the item list while clearing existing items.
• Add: Adds a PWL or TXT file to the item list. Does not clear existing items.
• Export: Exports selected power lines to DXF or shapefile format.

Once items have been added to the list, it is possible to modify them. Power lines may be selected or deselected, this will show them or not. Power lines may be renamed and their colors may be changed. Right clicking on a specific power line shows a contextual menu:

• Check all: Selects all power lines in the list; displaying all items on the screen.
• Uncheck all: Deselects all power lines in the list; hiding items on the screen.
• Delete current: Deletes the currently selected power line.
• Split: Activates the split function. The line to be split does not necessarily have to be the selected line.
• Merge: Activates the merge fucntion. The lines to be merged can be any lines displayed on the screen.

It is also possible to expand a power line to view the points contained in the line. Click on Points to expand a power line and view the list. By right clicking on a point in the list, a contextual menu adds a few extra options.

• Hide points: Collapses the current power line, hiding the list of points.
• Remove all: Empties the points in the list. The power line will contain 0 points.
• Remove current: Removes the current point from the list.
• Insert: Adds a point before the current point and updates the point list.
• Repick: Allows the user to repick the selected point. The selected point should be highlighted in red on the screen.

Detection

To begin detecting power lines, expand the detection portion of the window and review the options available.

• Min. segm. length: This option determines the minimum segment length that will be detected. The smaller this value is, the more points will be detected per power line.
• Max. segm. length: This option determines the maximum segment length that will be detected. The larger this value is, the less points will be detected per power line.
• Max. Z distance: This option determines the maximum distance in elevation (Z) that will be tolerated. Sometimes when power lines are not being detected completely, it can be helpful to increase this value a little bit. However, if the maximum Z distance is too high, the algorithm may confuse neighboring power lines as being the same.
• Max. XY distance: This option determines the maximum distance in planimetry (X and Y) that will be tolerated. Sometimes when power lines are not being detected completely, it can be helpful to increase this value a little bit. However, if the maximum X and Y distance is too high, the algorithm may confuse neighboring power lines as being the same.
• Search radius: This value determines the search radius for detecting other power lines. The seach radius will be used only if the option Single line is unchecked, meaning that multiple lines will be detected at a time.
• Min. dist. betw. lines: This value determines the minimal distance between two detected lines. This option was added to avoid detecting too many lines in a given area.
• Starting point: The starting point is an XYZ coordinate in the project that will determine the point from which the detection will begin. This point may be set by clicking on the … button and clicking on a power line on the screen.
• Single line: This option can be checked to detect only one power line at a time. If this option is unchecked, multiple lines will be detected.
• Start detection: Clicking on this button will begin the power line detection with the specified settings. All detected power lines will be added to the list on the left of the window.

Add manually

In this section it is possible to add a power line manually. This option can be used for hard-to-detect power lines or for lines that require a specific vectorization.

• Add a line: This button will add an empty line to the list of power lines on the left of the window.
• Start/Stop pick: After clicking on Add a line, the Start pick mode is automatically active. This will set the tool to picking mode – where the user may vectorize a power line manually by clicking on points in the main screen. Once picking the line is complete, click on Stop pick to exit picking mode.

It’s also possible to add points to an existing line. Simply select the line in the list and click on Start pick. Pick as many points as necessary and click on Stop pick to exit picking mode.

Classify

The classification tool is used to classify power lines to a specific class.

• Class: A class number must be entered here. For example, if the number 15 is entered, all points within the given radius will be marked as belonging to class 15. The user may also rename any class in the Explorer to match its contents.
• Radius: The radius within which a point in the point cloud will be considered as a power line and therefore will be classified as such. For thick power lines, use a larger radius.

Clash detection

The clash detection tool works similarly to the classify tool, except in this case any objects which are close to the power lines will be classified to a given class. This can be quite useful to detect nearby trees, branches, poles, or any other type of obstruction and send them to a specific class to hightlight the obstruction.

• Class: A class number must be entered here. For example, if the number 16 is entered, all points within the clash detection area will be marked as belonging to the class 16. The user may also rename any class in the Explorer to match its contents.
• Skip class: A class number must be entered here. Any point within the clash detection area that is part of the skip class will not be considered and therefore will not be reclassified.
• Clash radius: The radius used for the clash detection. Any points within the given radius will be classified to the specified class.
• Inner radius: The radius used for the power line itself. The inner radius is not reclassified.