Changes between Version 21 and Version 22 of Help/LeicaLidarDems


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Timestamp:
May 20, 2009 5:50:48 PM (10 years ago)
Author:
mark1
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  • Help/LeicaLidarDems

    v21 v22  
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    103 To extend the coverage of your DEM, if required, it is suggested to patch on external DEM data. If you have access to a good quality DEM then use that, else the SRTM 3 arc second DEM is freely available and covers most of the globe between +-60 degrees latitude. To see how to make a DEM from SRTM data see the [wiki:Processing/SRTMDEMs SRTM DEM] page. Make sure to select the projection  the same as your LIDAR DEM.
     103To extend the coverage of your DEM, if required, it is suggested to patch on external DEM data. If you have access to a good quality DEM then use that, else the SRTM 3 arc second DEM is freely available and covers most of the globe between +-60 degrees latitude. To see how to make a DEM from SRTM data see the [wiki:Processing/SRTMDEMs SRTM DEM] page. Make sure to select the projection  the same as your LIDAR DEM. Also, be aware that the SRTM elevations are with respect to a geoid model and will need to be converted to the LIDAR vertical datum.
    104104
    105105Once you have an SRTM DEM of sufficient coverage you can patch the LIDAR and SRTM DEMs together, such that the LIDAR takes precedence. This means the lidar_dem should be the first of the input maps on the r.patch command. If the mask is still applied then remove it before patching: