Changes between Version 13 and Version 14 of Processing/laguserguide


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Timestamp:
May 24, 2012 4:18:48 PM (7 years ago)
Author:
jaho
Comment:

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  • Processing/laguserguide

    v13 v14  
    6262LAG currently supports UTM and latlong (or longlat: x = longitude, y = latitude) projections. By default files in both formats will be displayed using UTM coordinates. You can change it by going to //Tools >> Use latlong coordinates//.
    6363
    64 Latlong is generally a preferred projection because it doesn't require additional zone information. Latlong files can be saved as both latlong and UTM, while UTM files should not be converted, unless they contain projection information in the header's VLR geo keys. Alspp produced UTM files don't contain this information (they do but under wrong GeoKey) so this conversion should be avoided for the time being. Also latlong files seem to have higher precision than UTM files (up to about a 10th of a milimeter), which is probably much higher than the actual lidar precision. By default this values are rounded to precision of 1 centimeter when converting latlong to UTM. To prevent precision loss you can select // Use full precision // option on file saver dialog, however this will result in bigger files.
     64Latlong is generally a preferred projection because it doesn't require additional zone information. Latlong files can be saved as both latlong and UTM, while UTM files should not be converted, unless they contain projection information in the header's VLR geo keys. Alspp produced UTM files don't contain this information (they do but under wrong GeoKey) so this conversion should be avoided for the time being. Also latlong files seem to have higher precision than UTM files (up to around 10th of a milimeter), which is probably much higher than the actual lidar precision. By default this values are rounded to precision of 1 centimeter when converting latlong to UTM. To prevent precision loss you can select // Use full precision // option on file saver dialog, however this will result in bigger files.
    6565
    6666== Other Options ==
     
    7070    This redraws all the points from buckets. Whenever it happens that part of the data has not been rendered correctly or when not using //Full refresh on panning// pressing //Refresh// should fix any problems.
    7171* **Vertical slicing**
    72     This allows to only display points within given Z values range. When //Slice// option is enabled all operations, like taking a profile and classifying, will only apply to the points with elevation within specified range.
     72    This allows to only display points within given Z values range. When //Slice// option is enabled all operations, like loading a profile and classifying, will only apply to the points with elevation within specified range.
    7373* **Super Zoom**
    7474    This option is useful for close points inspection. It makes zooming in and out faster by the factor of 10 and also increases the point size.
     75* **Heights**
     76    Displays average Z values of points loaded into the profile and, in case of multiple flightlines, altitude differences between them in cm.
     77* **Tools>Quadtree Information**
     78    Shows information about the quadtree: number of points, number of buckets, cache size, boundaries and projection information if available.