Changes between Version 11 and Version 12 of Processing/LidarCalibrationProcedure


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Timestamp:
May 7, 2009 9:44:32 AM (10 years ago)
Author:
mark1
Comment:

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  • Processing/LidarCalibrationProcedure

    v11 v12  
    3636 * Look at the filesizes of the output data.  If the ATN.LAS files are over 400MB in size then Attune will not run. If this is the case re-process with only the part of interest of the line.
    3737   * Part of interest will be the area where all flight lines overlap.
    38 3. Ground classification needs to be performed on the files before tie pointing in Attune. But to load the ATN.LAS files into Terrascan we need to first import them into Attune to convert them. To do this follow the first step of 4. below and import the .bin files into Terrascan.
     383. Ground classification needs to be performed on the files before tie pointing in Attune. But to load the ATN.LAS files into Terrascan we need to first import them into Attune to convert them. To do this we need to start the Attune software
    3939 * We do this so that we only use points on the ground in the tie pointing (since we don't want errors due to perspective or shadowing)
    40  * Ground classification procedures can be found [wiki:Sensors/LeicaLIDAR/MashUp#Groundclassification here]
    41 
    42 4. Start Attune and tie point the data
    43  * Add ALS data -> add the real ATN.LAS files from the ALSPP output
     40 * In Attune - Add ALS data -> add the real ATN.LAS files from the ALSPP output
    4441   * The suggested pixel sizes (from top level calibration pdf) are 0.3m for 750m, 0.4m for 1350m and 0.8m for 2300m.
    4542 * View the image pngs to make sure no data holes. (Some are OK. Re-load using a different resolution if too many holes. e.g. Try 0.35m for 750m)
    4643   * 'a' centres the image
    4744   * '+/-' to zoom in/zoom out
     45 * There should now be some files with .bin extension. These can be imported into Terrascan for ground classification.
     46 * Ground classification procedures can be found [wiki:Sensors/LeicaLIDAR/MashUp#Groundclassification here]
     47
     484. Once the data have been ground classified re-start Attune and tie point the data
    4849 * Now select tie points. We use streets for tie points since these should be on the ground so no (little) effects due to look angles and also has slow varying topography
    4950   * Open tie point editor in Attune.