Changes between Version 42 and Version 43 of Processing/Lidarqcprocedure


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Timestamp:
May 19, 2010 12:49:12 PM (10 years ago)
Author:
knpa
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  • Processing/Lidarqcprocedure

    v42 v43  
    1 = Lidar QC Procedure =
    2 
    3 This page describes the procedure for the QC of the LIDAR data.
    4 ------
    5 == QC Procedure ==
     1== LIDAR QC Procedure ==
    62
    73As it stands this is the Lidar data QC procedure. This could be improved and added to as time allows.
    84
    95=== Check overlap of neighbouring lines ===
    10 
    11 ==== Horizontal ====
    12 The first thing to do here is to load up all lines into a viewer (or if runs out of memory load them up in pairs) and see how well they overlap in the horizontal plane. The Fugro viewer is probably best for this because it also allows Shapefiles to be read in (though you can also just use Terrascan with "Colour by intensity").
    13 Check along features that cross between flight lines, for example, roads/field boundaries/hedgerows do they continue unbroken or are they offset between flight lines. Also, compare against the vectors (if available) for any gross offsets.
    146
    157==== Vertical ====
     
    2315
    2416
     17==== Horizontal ====
     18The first thing to do here is to load up all lines into a viewer (or if runs out of memory load them up in pairs) and see how well they overlap in the horizontal plane. The Fugro viewer is probably best for this because it also allows Shapefiles to be read in (though you can also just use Terrascan with "Colour by intensity").
     19Check along features that cross between flight lines, for example, roads/field boundaries/hedgerows do they continue unbroken or are they offset between flight lines. Also, compare against the vectors (if available) for any gross offsets.
     20
     21
    2522=== Check against OS vector maps ===
    2623
     
    3128To check in Terrascan: You need to convert the .shp vectors into .dgn. Instructions [wiki:Processing/shapesintoterrascan here]
    3229
    33 === Reclassify noisy points ===
     30=== Classify noisy points ===
    3431
    3532
     
    3734
    3835The final 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, or using a (in-progress) program [wiki:Processing/LidarClassification classify_las].
     36[[BR]]
     37
     38
     39'''Microstation method'''
     40[[BR]]
    3941
    4042Start Microstation and goto Utilities -> MDL Applications -> Terrascan[[BR]]
    4143In Terrascan goto Tools -> Macro
    42 
    4344Press Add to add routines to the Macro.
    44 
    4545 * Change all classes to default class (Action: Classify Points, Routine: by class)
    4646 * Classify groups of low points (Action: Classify Points, Routine: low points)