====== Clearance Checker ====== 

This page describes the Orbit desktop extension "Clearance Checker". 

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===== Concepts =====

The Clearance checker extension calculates the lowest clearance of overhanging objects or constructions above a surface.\\

===== Source =====

Use the generic workflow for [[237:desktop_ext:generic|]] to define the source file. 

The method for the range of interest is 'Path', 'Multiple Paths', 'Area' and 'Multiple Areas'. 

===== Supplement, Group By =====

Select how the clearance obstructions are grouped by:

** Clusters ** - For every area or path, the point cloud gets divided into clusters. For each cluster, the lowest clearance will be calculated. 

** Ranges ** - For every area or path, the lowest clearance will be calculated.

===== Ground Reference =====

Choose one of the below-described options to define the Ground Reference:

** Point Cloud lowest Z ** - The lowest z-value of the point cloud.

** Point Cloud Z below trajectory ** - The lowest z-value of the first point cloud cluster found below the trajectory.

** Trajectory offset ** - Fixed vertical offset from the trajectory. \\
A trajectory needs to be defined in block **Trajectory**: a new path can be drawn or selected. \\
Vertical offset needs to be defined in parameters.

** Fixed height ** - Fixed z-value defined in parameters.

** Use paths ** - The source path(s) are used to set the ground reference. 

===== Parameters =====

Generic concepts, see [[237:desktop:preferences:detectors|]]

Some parameters are greyed out based on the options previously selected.


===== Results =====

The Hit count is the number of clearances found. 

  * **Z range**: Value of the clearance.
  * **#pnts**: Number of points defining the ceiling of the clearance.

DEM files are added to the Dataset List by default and are saved in the corresponding folder (see above). 
  * **Clearance**
  * **Cluster_min_clearance**
  * **Ground**
  * **Pixel_z_range**

===== Clearance Checker Tab =====

In the Clearance Checker Tab all Clearance Projects are shown including the results and metadata. Standard operations like detaching and maximizing tab are available.

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