Changes between Version 30 and Version 31 of Processing/Lidarqcprocedure


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Timestamp:
Sep 21, 2009 11:51:56 AM (10 years ago)
Author:
emca
Comment:

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  • Processing/Lidarqcprocedure

    v30 v31  
    1212'''Using Macros'''
    1313
    14 The first stage of the QC is to check the data and reclassify erroneous points. This can be done in Microstation/TerraSolid by creating a macro. It should be straightforward to script this into a GIS such as GRASS too.
     14The first stage of the QC is to check the data and reclassify erroneous points to class 7 (low points). This can be done in Microstation/TerraSolid by creating a macro. It should be straightforward to script this into a GIS such as GRASS too.
    1515
    1616Start Microstation and goto Utilities -> MDL Applications -> Terrascan[[BR]]
     
    2424 * Classify isolated points (Action: Classify Points, Routine: isolated points)
    2525
    26 To run on large projects use "selected files" instead of reading all LAS files into memory.
     26To run on large projects use "selected files" instead of reading all LAS files into memory. Ensure that the output format under 'Save As:' is .LAS 1.0.
    2727
    28 Ensure that the output format under 'Save As:' is .LAS 1.0.
    2928
    30 Check the result to see what points have been selected.
    3129
    3230To remove haze layers, use elevation to threshold (Routine: by absolute elevation). Select an elevation range whose minimum is well above any ground targets and maximum above the haze layer.
     
    3836'''Note: Manually reclassifying points can only be done on a per flight line basis.'''
    3937
    40 Can use the Assign tool from the Classify menu to amend points which were missed or wrongly classified by the classification algorithms. Select the required options on the 'from' and 'to class'  drop down boxes and individually select a point to reclassify it.
     38Check the result to see what points have been classified using the macro. There may be points which were missed or wrongly classified by the classification algorithms.
     39
     40Can use the Assign tool from the Classify menu reclassify individual points. Select the required options on the 'from' and 'to class' drop down boxes and individually select a point to reclassify it.
    4141
    4242If there are a large number of points to be reclassified manually there are several tools (available by clicking on the 'Create Editable Model' icon) which allow groups of points to be reclassified. Be careful if using the 'Classify Using Brush' tool. This tool becomes active once the left mouse button has been clicked and reclassified anything that falls with the region indicated by the mouse icon. Right click with the mouse to deactivate this tool.