Changes between Version 22 and Version 23 of Sensors/LeicaLIDAR/MashUp


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Timestamp:
Mar 16, 2010 3:55:56 PM (10 years ago)
Author:
emca
Comment:

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  • Sensors/LeicaLIDAR/MashUp

    v22 v23  
    153153The general processing procedure is as follows:
    154154 * Trajectory processing
    155    * see the pages on GrafNav and IPAS processing
     155   * see the pages on !GrafNav and IPAS processing
    156156 * ALS post processor to convert raw LIDAR scan data to binary LAS point cloud
    157157   * see the page on the ALS post processor
     
    209209   * find altitude over ground (measured GPS alt - geoid-spheroid height) and see if it's within the min & max ranges
    210210 * check the speed they were flying at is not too fast
    211  * check the images in TerraScan
     211 * check the images in !TerraScan
    212212 * look at start/stop times of points at end of flight line – do these match the flight logsheet
    213213
     
    221221== Full QC procedures ==
    222222
    223 The general processing data QC-ing should primarily take the form of viewing the intensity images to check for striping and to see if they look “correct” i.e. Does it look like the area surveyed. The data should be loaded into TerraScan and checked that all the flight lines line up OK both spatially and vertically (check cross sections around the image).
     223The general processing data QC-ing should primarily take the form of viewing the intensity images to check for striping and to see if they look “correct” i.e. Does it look like the area surveyed. The data should be loaded into !TerraScan and checked that all the flight lines line up OK both spatially and vertically (check cross sections around the image).
    224224
    225225The main things are:
     
    406406 * In ALSPP uncheck the “average last returns” option in the settings dialog.
    407407 * Check the output as attune files in the outputs dialog
    408  * Add all the flight data into the ALSPP, including the BIT mode data, and run the RangeCardCal program from the utilities menu.  Select the use all SCN files option when prompted. 
     408 * Add all the flight data into the ALSPP, including the BIT mode data, and run the !RangeCardCal program from the utilities menu.  Select the use all SCN files option when prompted. 
    409409   * This gets the differences for range card banks A & B.  Takes differences R1-RL and averages them. Similarly for R2-RL, R3-RL, R4-RL.
    410410 * Enter range offset A1 as 0 since it is unknown.
     
    451451   * When happy save the solution
    452452 * Return to ALSPP and add the Roll, Pitch and Heading values to the boresight calibration dialog. Change the outputs to LAS not Attune. Change the output directory too.  Re-run the processing.
    453  * Analyse the results in TerraScan
     453 * Analyse the results in !TerraScan
    454454   * Check cross sections etc for misaligning flightlines.
    455455   * To load all flightlines will probably need to use a fence (this is like a region of interest)
     
    513513
    514514 * In ALSPP filters dialog set the angles to +7 and -7 degrees, change the output directory (to 02a_Roff+-7deg if using suggested directory structure) and run the processing on the 4 low altitude flight lines.
    515  * Load the results into TerraScan and use the 30-40 GCPs of the calibration site.
     515 * Load the results into !TerraScan and use the 30-40 GCPs of the calibration site.
    516516 * Tools -> Output Control Report
    517517 * Browse -> GCP file and remove bad points (maybe an error occurred in the surveying of a certain point)
     
    519519 * Save the text file.
    520520
    521 Preferably using data including areas of forest and the BIT mode data, run RangeCardCal (from ALSPP tools menu) and enter the average dz value as A1 to get the other offsets. Add the outputs to the ALSPP dialog and save the settings reg file (to a new name)
    522 
    523 To check these results re-run using the full FOV (~45 degrees) and check average dz is less than 1cm or so, and standard deviation <5cm in TerraScan control report. (also look at cross sections)
    524 
    525 Then process the 4 high altitude flights in ALSPP and check in TerraScan (around nadir and swath edges)
    526 
    527 Finally load in all flights into TerraScan (within a fence if memory issues) and check them (ideally along a stream because this has a “good” profile) Can use the travel path tool in TerraScan for comparing cross sections along a path.
     521Preferably using data including areas of forest and the BIT mode data, run !RangeCardCal (from ALSPP tools menu) and enter the average dz value as A1 to get the other offsets. Add the outputs to the ALSPP dialog and save the settings reg file (to a new name)
     522
     523To check these results re-run using the full FOV (~45 degrees) and check average dz is less than 1cm or so, and standard deviation <5cm in !TerraScan control report. (also look at cross sections)
     524
     525Then process the 4 high altitude flights in ALSPP and check in !TerraScan (around nadir and swath edges)
     526
     527Finally load in all flights into !TerraScan (within a fence if memory issues) and check them (ideally along a stream because this has a “good” profile) Can use the travel path tool in !TerraScan for comparing cross sections along a path.
    528528
    529529
     
    563563 * The tie points that you will later select will presumably avoid areas such as trees, so you don't need to really worry about these when classifying
    564564
    565  * In TerraScan load in a LAS file.
     565 * In !TerraScan load in a LAS file.
    566566 * Before ground classification we should remove noisy points.
    567567   * Default -> low points classification.
     
    605605
    606606--------------
    607 = TerraScan stuff =
    608 
    609 ''This should probably be moved to a separate TerraScan page when we get chance''
     607= !TerraScan stuff =
     608
     609''This should probably be moved to a separate !TerraScan page when we get chance''
    610610
    611611MAKE SURE YOU HAVE A 3D TEMPLATE LOADED UP (There is one in LiDAR folder on D: in Windows machine)
    612612 
    613  * It is possible to synchronise more than one viewer in TerraScan (as in Envi/ERDAS) so can look at intensity and elevation at the same point.
    614  * We can use TerraScan for creating projects, showing trajectories, splitting and combining LAS files.
     613 * It is possible to synchronise more than one viewer in !TerraScan (as in Envi/ERDAS) so can look at intensity and elevation at the same point.
     614 * We can use !TerraScan for creating projects, showing trajectories, splitting and combining LAS files.
    615615 * Create new project – “first button” -> “offset stacked rectangle button”
    616616
     
    626626 * Can then do things as normal to these project points.
    627627 * Can also recombine all the points to a single LAS file if required.
    628  * May want trajectory loaded up in TerraScan
     628 * May want trajectory loaded up in !TerraScan
    629629   * Setup ALSPP as if to process data.
    630630   * ALSPP -> utilities -> generate trj files.
    631    * Import into TerraScan and draw trajectory [use the “3 child squares” -> “parallel lines button”to import]
     631   * Import into !TerraScan and draw trajectory [use the “3 child squares” -> “parallel lines button”to import]
    632632   * The trajectory is important for removing overlaps of data or trimming data and other things.
    633633   * When cutting overlapping points we can use the “by quality” option – low flights take precedence but can also add a quality factor to points which will be used to weight. Alternatively can use the “by offset” option – defines an angle of flightline to cut by.