Changes between Version 4 and Version 5 of Sensors/LeicaLIDAR/MikesNotes


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Timestamp:
Aug 26, 2008 3:15:24 PM (11 years ago)
Author:
mggr
Comment:

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  • Sensors/LeicaLIDAR/MikesNotes

    v4 v5  
    1515Flying too low - if the LIDAR detects that the laser power may be too high for eye safety, it will cut out the laser automatically (if you're a seagull looking up, bad luck, it only accounts for ground height).
    1616
     17Flying outside the "range gate" (acceptable ranges of distances) may cause similar effects.  Going too high will tend to make the edges of the swath drop out first (due to path length).
     18
    1719Automatic gain control weirdness - the measured intensity is returned via an AGC which may step up or down depending on the returns from the ground.  Measured return intensity should only be used as a guideline rather than a real measurement.
    1820
    1921Water absorbs IR, so expect poor returns from wet surfaces.  Ideally one should wait for a whole dry day after rain.
     22
     23
     24== Mission planning considerations ==
     25
     26Water absorbs IR, so expect poor returns from wet surfaces.  Ideally one should wait for a whole dry day after rain.
     27
     28For differential GPS, aim to have a base station nearby (within 20km) and ideally in center of the scene.  Base station data should be recorded at 2Hz
     29
     30Ideally choose a time with a good GPS constellation (lots of satellites, PDOP >= 4).
     31
     32Consider terrain and minimum target size to determine required point density.  Steep terrain may cause shadowing effects due to perspective.
    2033
    2134== Overall system design and comments of note ==