1:: 2:: Ways to generate raster Canopy Height Model (CHM) with LAStools ... (-: 3:: 4:: Read more at 5:: 6:: http://rapidlasso.com/2014/11/04/rasterizing-perfect-canopy-height-models-from-lidar/ 7:: 8 9set PATH=%PATH%;D:\LAStools\bin; 10 11:: global definitions 12 13set MUNICIPALITY=tab 14set BLOCK=vsu 15set STEP=0.5 16set SUBGRIDSTEP=0.25 17set KILL=1.5 18set MIN_MAX=0 15 19set CORES=6 20 21:: below are all the used command lines used in this article 22 23:: tile the LiDAR 24 25:: ground classify LiDAR 26 27:: normalize the LiDAR data 28 29lasheight -i %BLOCK%\tiles_ground\%MUNICIPALITY%*.laz ^ 30 -replace_z ^ 31 -classify_below -2 7 ^ 32 -classify_above 50 7 ^ 33 -odir %BLOCK%\tiles_normalized -olaz ^ 34 -cores %CORES% 35 36:: create CHM simply with highest point per grid cell with lasgrid 37 38lasgrid -i %BLOCK%\tiles_normalized\%MUNICIPALITY%*.laz ^ 39 -step %STEP% -highest ^ 40 -false -set_min_max %MIN_MAX% ^ 41 -use_tile_bb ^ 42 -odir %BLOCK%\tiles_chm -odix "_grd_d00" -opng ^ 43 -cores %CORES% 44 45:: same as above but "splat" points into small circles with diameter 20 cm 46 47:GRID_D20 48 49lasgrid -i %BLOCK%\tiles_normalized\%MUNICIPALITY%*.laz ^ 50 -subcircle 0.1 ^ 51 -step %STEP% -highest ^ 52 -false -set_min_max %MIN_MAX% ^ 53 -use_tile_bb ^ 54 -odir %BLOCK%\tiles_chm -odix "_grd_d20" -opng ^ 55 -cores %CORES% 56 57:: create CHM by rasterizing TIN of all first returns with las2dem 58 59:TIN_D00 60 61las2dem -i %BLOCK%\tiles_normalized\%MUNICIPALITY%*.laz ^ 62 -first_only ^ 63 -step %STEP% ^ 64 -false -set_min_max %MIN_MAX% ^ 65 -use_tile_bb ^ 66 -odir %BLOCK%\tiles_chm -odix "_tin_d00" -opng ^ 67 -cores %CORES% 68 69:: create CHM by rasterizing TIN of highest point per finer (sub-)grid cell after "splatting" points into small frisbees of 20 cm diameter 70 71:TIN_D20 72 73rmdir %BLOCK%\tmp_dir /s /q 74mkdir %BLOCK%\tmp_dir 75 76lasthin -i %BLOCK%\tiles_normalized\%MUNICIPALITY%*.laz ^ 77 -subcircle 0.1 ^ 78 -step %SUBGRIDSTEP% -highest ^ 79 -odir %BLOCK%\tmp_dir -olaz ^ 80 -cores %CORES% 81 82las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 83 -step %STEP% ^ 84 -false -set_min_max %MIN_MAX% ^ 85 -use_tile_bb ^ 86 -odir %BLOCK%\tiles_chm -odix "_tin_d20" -opng ^ 87 -cores %CORES% 88 89rmdir %BLOCK%\tmp_dir /s /q 90 91:: create CHM with modified pit-free algorithm 92 93:PIT_FREE 94 95rmdir %BLOCK%\tmp_dir /s /q 96mkdir %BLOCK%\tmp_dir 97 98lasthin -i %BLOCK%\tiles_normalized\%MUNICIPALITY%*.laz ^ 99 -subcircle 0.1 ^ 100 -step %SUBGRIDSTEP% -highest ^ 101 -odir %BLOCK%\tmp_dir -olaz ^ 102 -cores %CORES% 103 104las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 105 -drop_z_above 0.1 ^ 106 -step %STEP% ^ 107 -use_tile_bb ^ 108 -odir %BLOCK%\tmp_dir -odix "_chm_GP" -obil ^ 109 -cores %CORES% 110 111las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 112 -step %STEP% ^ 113 -kill %KILL% ^ 114 -use_tile_bb ^ 115 -odir %BLOCK%\tmp_dir -odix "_chm_00" -obil ^ 116 -cores %CORES% 117 118las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 119 -drop_z_below 2 ^ 120 -step %STEP% ^ 121 -kill %KILL% ^ 122 -use_tile_bb ^ 123 -odir %BLOCK%\tmp_dir -odix "_chm_02" -obil ^ 124 -cores %CORES% 125 126las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 127 -drop_z_below 5 ^ 128 -step %STEP% ^ 129 -kill %KILL% ^ 130 -use_tile_bb ^ 131 -odir %BLOCK%\tmp_dir -odix "_chm_05" -obil ^ 132 -cores %CORES% 133 134las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 135 -drop_z_below 8 ^ 136 -step %STEP% ^ 137 -kill %KILL% ^ 138 -use_tile_bb ^ 139 -odir %BLOCK%\tmp_dir -odix "_chm_08" -obil ^ 140 -cores %CORES% 141 142las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 143 -drop_z_below 11 ^ 144 -step %STEP% ^ 145 -kill %KILL% ^ 146 -use_tile_bb ^ 147 -odir %BLOCK%\tmp_dir -odix "_chm_11" -obil ^ 148 -cores %CORES% 149 150las2dem -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.laz ^ 151 -drop_z_below 14 ^ 152 -step %STEP% ^ 153 -kill %KILL% ^ 154 -use_tile_bb ^ 155 -odir %BLOCK%\tmp_dir -odix "_chm_14" -obil ^ 156 -cores %CORES% 157 158lasgrid -i %BLOCK%\tmp_dir\%MUNICIPALITY%*.bil -merged ^ 159 -step %STEP% ^ 160 -highest ^ 161 -false -set_min_max %MIN_MAX% ^ 162 -use_bb ^ 163 -o %BLOCK%\chm_pit_free.png 164 165rmdir %BLOCK%\tmp_dir /s /q 166 167 168 169 170