Changes between Version 22 and Version 23 of Sensors/LeicaLIDAR/MashUp
- Timestamp:
- Mar 16, 2010, 3:55:56 PM (14 years ago)
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Sensors/LeicaLIDAR/MashUp
v22 v23 153 153 The general processing procedure is as follows: 154 154 * Trajectory processing 155 * see the pages on GrafNav and IPAS processing155 * see the pages on !GrafNav and IPAS processing 156 156 * ALS post processor to convert raw LIDAR scan data to binary LAS point cloud 157 157 * see the page on the ALS post processor … … 209 209 * find altitude over ground (measured GPS alt - geoid-spheroid height) and see if it's within the min & max ranges 210 210 * check the speed they were flying at is not too fast 211 * check the images in TerraScan211 * check the images in !TerraScan 212 212 * look at start/stop times of points at end of flight line – do these match the flight logsheet 213 213 … … 221 221 == Full QC procedures == 222 222 223 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).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). 224 224 225 225 The main things are: … … 406 406 * In ALSPP uncheck the “average last returns” option in the settings dialog. 407 407 * 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. 409 409 * 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. 410 410 * Enter range offset A1 as 0 since it is unknown. … … 451 451 * When happy save the solution 452 452 * 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 TerraScan453 * Analyse the results in !TerraScan 454 454 * Check cross sections etc for misaligning flightlines. 455 455 * To load all flightlines will probably need to use a fence (this is like a region of interest) … … 513 513 514 514 * 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. 516 516 * Tools -> Output Control Report 517 517 * Browse -> GCP file and remove bad points (maybe an error occurred in the surveying of a certain point) … … 519 519 * Save the text file. 520 520 521 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 inTerraScan for comparing cross sections along a path.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. 528 528 529 529 … … 563 563 * 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 564 564 565 * In TerraScan load in a LAS file.565 * In !TerraScan load in a LAS file. 566 566 * Before ground classification we should remove noisy points. 567 567 * Default -> low points classification. … … 605 605 606 606 -------------- 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'' 610 610 611 611 MAKE SURE YOU HAVE A 3D TEMPLATE LOADED UP (There is one in LiDAR folder on D: in Windows machine) 612 612 613 * 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. 615 615 * Create new project – “first button” -> “offset stacked rectangle button” 616 616 … … 626 626 * Can then do things as normal to these project points. 627 627 * Can also recombine all the points to a single LAS file if required. 628 * May want trajectory loaded up in TerraScan628 * May want trajectory loaded up in !TerraScan 629 629 * Setup ALSPP as if to process data. 630 630 * 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] 632 632 * The trajectory is important for removing overlaps of data or trimming data and other things. 633 633 * 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.