**************************************************************** this file is deprecated - see *.md version of this file **************************************************************** lastrack: This tool takes one (or many) LAS or LAZ files together with a trajectory file that must have matching GPS time stamps. It then computes the height of each point above this trajectory plus a constant offset. This '-offset -1.93' parameter allows to subtract the elevation of the GPS unit above the ground for a mobile survey by lowering (or raising) the trajectory to be at the level of the road surface. Is is important that both - the files with the LiDAR points the files with the trajectory points - do not only have the same GPS time stamps but are also in the same projection. Should the input coordinates be in some representation where the z-axis does not correspond to elevation, such as in an earth-centered representation, then all the files need to be converted to, for example, a UTM projection first. Commonly this is used with switches '-classify_below -0.4 7' which classifies all points that are 40 centimeter or lower than track (plus offset) as point class 7 (low noise). Similar options are '-classify_between -0.4 0.5 2' classifying all points between 40 below and 50 centimeter above the track (plus offset) as point class 2 (ground). The corresponding option '-classify_below 37.5 25' also exists. Alternatively you can '-replace_z' the original elevation value of each point with the computed height. That means all points will have an elevation that equals their height above (or below) the track (plus offset). This will "normalize" the elevations of the points in respect to the recorded trajectory. Another alternative is to use the computed height to eliminate points with a particular height above or below a threshold with options '-drop_below 1.5' or '-drop_above 6.8'. It is also possible to classify points in a particular x/y range from the trajectory with '-classify_xy_range_between min max class' that takes three parameters. It classifies any point within the specified min/max range from the trajectory as specified. Similar, '-classify_xy_range_and_height_between min max min_h max_h class' classifies any point within the specified min/max range from the trajectory as specified but only if their height is between min_h and max_h above (or below) the trajectory (plus offset). With the '-classify_xyz_range_between min max class' classification will be done using the 3D distance between point and trajectory. You can also store the computed height and the range values as additional point attributs via "extra bytes" using one of these -store_height_as_extra_bytes -store_height_precise_as_extra_bytes -store_xy_range_as_extra_bytes -store_xy_range_precise_as_extra_bytes -store_xyz_range_as_extra_bytes -store_xyz_range_precise_as_extra_bytes Height ist stored as signed 16 Bit integer. Resolution is cm, so you will have values between (-327.68 - 327.67 m). Height_precise ist stored as 32 Bit integer/1000. Resolution is mm, so you will have values between (−2147483.648 - 2147483.647 m). Range is stored as unsigned 16 Bit integer/100 (0 - 655.35 m). Range_precise as unsigned 32 Bit integer/1000 (0 - 4294967.295 m). So if your values might get big and you dont want to risk an integer overflow use the _precise version of the parameter. Please license from info@rapidlasso.de before using lastrack commercially. For updates check the website or join the LAStools mailing list. http://lastools.org/ http://groups.google.com/group/lastools/ Jochen @lastools **************************************************************** example usage: >> lastrack -i *.las ^ -track track.laz ^ -offset -2.12 ^ -drop_below -1.2 ^ -odix _cleaned -olaz computes for all points from the LAS files that match '*.las' the heights above their by 2.12 meters lowered trajectory provided as file 'track.laz' and drops all points whose height is below -1.20 and stores them with an appendix '_cleaned' as compressed LAZ. >> lastrack -i tj0012\*.laz ^ -track tj0012.laz ^ -offset -2.47 ^ -classify_below -0.4 7 ^ -classify_between -0.4 0.5 2 ^ -classify_between 3 10 25 ^ -odix _classed -olaz computes for all points from the LAZ files matching 'tj0012\*.laz' the heights above their by 2.47 meters lowered trajectory provided as file 'tj0012.laz' and classifies points whose height is below -0.40 as 7, all points whose height is between -0.40 as 0.50 as 2, and all points whose height is between 3.00 as 10.00 as 25 and stores them with an appendix '_classed' as compressed LAZ. >> lastrack -i session017\*.laz ^ -track s017.laz ^ -offset -1.84 ^ -replace_z ^ -odir session017_norm -odix _normalized -olaz computes for all points from LAZ files matching 'session017\*.laz' the heights above their by 1.84 meters lowered trajectory provided as file 's017.laz', normalizes the points by replacing their z values with with this height, and then stores them with appendix '_normalized' as compressed LAZ into directory 'session017_norm'. **************************************************************** overview of all tool-specific switches: -v : more info reported in console -vv : even more info reported in console -quiet : nothing reported in console -version : reports this tool's version number -fail : fail if license expired or invalid -gui : start with files loaded into GUI -cores 4 : process multiple inputs on 4 cores in parallel -ignore_class 1 3 4 5 6 7 9 : ignores points with specified classification codes -track trajectory4.laz : specifies file containing trajectory with GPS time -offset -2.4 : constant vertical offset from trajectory to ground (for mobile scans by truck or boat) -replace_z : replace z values of points with vertical distance above / below (offset) trajectory -drop_below -0.2 : drop points with vertical distance of -0.2 or lower from (offset) trajectory -drop_above 20.0 : drop points with vertical distance of 20.0 or higher from (offset) trajectory -drop_between 3.0 4.0 : drop points with vertical distance between 3.0 and 4.0 from (offset) trajectory -classify_below -0.2 7 : classify points with vertical distance of -0.2 or lower from (offset) trajectory as 7 -classify_above 20.0 7 : classify points with vertical distance of 20.0 or higher from (offset) trajectory as 7 -classify_between 3.0 4.0 10 : classify points with vertical distance between 3.0 and 4.0 from (offset) trajectory as 10 -classify_xy_range_between 2 4 12 : classify points with xy-distance between 2.0 and 4.0 from trajectory as 12 -classify_xy_range_and_height_between 0 3 -5 5 7 : classify points with xy-distance between 0.0 and 3.0 from trajectory and vertical distance between -5 and 5 from (offset) trajectory as 7 -classify_xyz_range_between 50 999 7 : classify points with xyz-distance between 50.0 and 999.0 from trajectory as 7 -store_height_as_extra_bytes : store height of points above trajectory with cm resolution -store_height_precise_as_extra_bytes : store height of points above trajectory with mm resolution -store_xy_range_as_extra_bytes : store xy distance between points and trajectory with cm resolution -store_xy_range_precise_as_extra_bytes : store xy distance between points and trajectory with mm resolution -store_xyz_range_as_extra_bytes : store xyz distance between points and trajectory with cm resolution -store_xyz_range_precise_as_extra_bytes : store xyz distance between points and trajectory with mm resolution -ilay : apply all LASlayers found in corresponding *.lay file on read -ilay 3 : apply first three LASlayers found in corresponding *.lay file on read -ilaydir E:\my_layers : look for corresponding *.lay file in directory E:\my_layers -olay : write or append classification changes to a LASlayers *.lay file -olaydir E:\my_layers : write the output *.lay file in directory E:\my_layers **************************************************************** for more info: E:\LAStools\bin>lastrack -h Filter points based on their coordinates. -keep_tile 631000 4834000 1000 (ll_x ll_y size) -keep_circle 630250.00 4834750.00 100 (x y radius) -keep_xy 630000 4834000 631000 4836000 (min_x min_y max_x max_y) -drop_xy 630000 4834000 631000 4836000 (min_x min_y max_x max_y) -keep_x 631500.50 631501.00 (min_x max_x) -drop_x 631500.50 631501.00 (min_x max_x) -drop_x_below 630000.50 (min_x) -drop_x_above 630500.50 (max_x) -keep_y 4834500.25 4834550.25 (min_y max_y) -drop_y 4834500.25 4834550.25 (min_y max_y) -drop_y_below 4834500.25 (min_y) -drop_y_above 4836000.75 (max_y) -keep_z 11.125 130.725 (min_z max_z) -drop_z 11.125 130.725 (min_z max_z) -drop_z_below 11.125 (min_z) -drop_z_above 130.725 (max_z) -keep_xyz 620000 4830000 100 621000 4831000 200 (min_x min_y min_z max_x max_y max_z) -drop_xyz 620000 4830000 100 621000 4831000 200 (min_x min_y min_z max_x max_y max_z) Filter points based on their return numbering. -keep_first -first_only -drop_first -keep_last -last_only -drop_last -keep_second_last -drop_second_last -keep_first_of_many -keep_last_of_many -drop_first_of_many -drop_last_of_many -keep_middle -drop_middle -keep_return 1 2 3 -drop_return 3 4 -keep_single -drop_single -keep_double -drop_double -keep_triple -drop_triple -keep_quadruple -drop_quadruple -keep_number_of_returns 5 -drop_number_of_returns 0 Filter points based on the scanline flags. -drop_scan_direction 0 -keep_scan_direction_change -keep_edge_of_flight_line Filter points based on their intensity. -keep_intensity 20 380 -drop_intensity_below 20 -drop_intensity_above 380 -drop_intensity_between 4000 5000 Filter points based on classifications or flags. -keep_class 1 3 7 -drop_class 4 2 -keep_extended_class 43 -drop_extended_class 129 135 -drop_synthetic -keep_synthetic -drop_keypoint -keep_keypoint -drop_withheld -keep_withheld -drop_overlap -keep_overlap Filter points based on their user data. -keep_user_data 1 -drop_user_data 255 -keep_user_data_below 50 -keep_user_data_above 150 -keep_user_data_between 10 20 -drop_user_data_below 1 -drop_user_data_above 100 -drop_user_data_between 10 40 Filter points based on their point source ID. -keep_point_source 3 -keep_point_source_between 2 6 -drop_point_source 27 -drop_point_source_below 6 -drop_point_source_above 15 -drop_point_source_between 17 21 Filter points based on their scan angle. -keep_scan_angle -15 15 -drop_abs_scan_angle_above 15 -drop_abs_scan_angle_below 1 -drop_scan_angle_below -15 -drop_scan_angle_above 15 -drop_scan_angle_between -25 -23 Filter points based on their gps time. -keep_gps_time 11.125 130.725 -drop_gps_time_below 11.125 -drop_gps_time_above 130.725 -drop_gps_time_between 22.0 48.0 Filter points based on their RGB/CIR/NIR channels. -keep_RGB_red 1 1 -keep_RGB_green 30 100 -keep_RGB_blue 0 0 -keep_RGB_nir 64 127 -keep_NDVI 0.2 0.7 -keep_NDVI_from_CIR -0.1 0.5 -keep_NDVI_intensity_is_NIR 0.4 0.8 -keep_NDVI_green_is_NIR -0.2 0.2 Filter points based on their wavepacket. -keep_wavepacket 0 -drop_wavepacket 3 Filter points based on extra attributes. -keep_attribute_above 0 5.0 -drop_attribute_below 1 1.5 Filter points with simple thinning. -keep_every_nth 2 -drop_every_nth 3 -keep_random_fraction 0.1 -keep_random_fraction 0.1 4711 -thin_with_grid 1.0 -thin_pulses_with_time 0.0001 -thin_points_with_time 0.000001 Boolean combination of filters. -filter_and Transform coordinates. -translate_x -2.5 -scale_z 0.3048 -rotate_xy 15.0 620000 4100000 (angle + origin) -translate_xyz 0.5 0.5 0 -translate_then_scale_y -0.5 1.001 -switch_x_y -switch_x_z -switch_y_z -clamp_z_below 70.5 -clamp_z 70.5 72.5 -copy_attribute_into_z 0 -copy_intensity_into_z Transform raw xyz integers. -translate_raw_z 20 -translate_raw_xyz 1 1 0 -translate_raw_xy_at_random 2 2 -clamp_raw_z 500 800 Transform intensity. -set_intensity 0 -scale_intensity 2.5 -translate_intensity 50 -translate_then_scale_intensity 0.5 3.1 -clamp_intensity 0 255 -clamp_intensity_above 255 -copy_RGB_into_intensity -copy_NIR_into_intensity Transform scan_angle. -scale_scan_angle 1.944445 -translate_scan_angle -5 -translate_then_scale_scan_angle -0.5 2.1 Change the return number or return count of points. -repair_zero_returns -set_return_number 1 -set_extended_return_number 10 -change_return_number_from_to 2 1 -set_number_of_returns 2 -set_number_of_returns 15 -change_number_of_returns_from_to 0 2 Modify the classification. -set_classification 2 -set_extended_classification 0 -change_classification_from_to 2 4 -classify_z_below_as -5.0 7 -classify_z_above_as 70.0 7 -classify_z_between_as 2.0 5.0 4 -classify_intensity_above_as 200 9 -classify_intensity_below_as 30 11 -classify_intensity_between_as 500 900 15 -change_extended_classification_from_to 6 46 -move_ancient_to_extended_classification Change the flags. -set_withheld_flag 0 -set_synthetic_flag 1 -set_keypoint_flag 0 -set_overlap_flag 1 Modify the extended scanner channel. -set_scanner_channel 2 -copy_user_data_into_scanner_channel Modify the user data. -set_user_data 0 -scale_user_data 1.5 -change_user_data_from_to 23 26 -change_user_data_from_to 23 26 -copy_attribute_into_user_data 1 Modify the point source ID. -set_point_source 500 -change_point_source_from_to 1023 1024 -copy_user_data_into_point_source -copy_scanner_channel_into_point_source -merge_scanner_channel_into_point_source -split_scanner_channel_from_point_source -bin_Z_into_point_source 200 -bin_abs_scan_angle_into_point_source 2 Transform gps_time. -set_gps_time 113556962.005715 -translate_gps_time 40.50 -adjusted_to_week -week_to_adjusted 1671 Transform RGB/NIR colors. -set_RGB 255 0 127 -set_RGB_of_class 9 0 0 255 -scale_RGB 2 4 2 -scale_RGB_down (by 256) -scale_RGB_up (by 256) -switch_R_G -switch_R_B -switch_B_G -copy_R_into_NIR -copy_R_into_intensity -copy_G_into_NIR -copy_G_into_intensity -copy_B_into_NIR -copy_B_into_intensity -copy_intensity_into_NIR Supported LAS Inputs -i lidar.las -i lidar.laz -i lidar1.las lidar2.las lidar3.las -merged -i *.las - merged -i flight0??.laz flight1??.laz -i terrasolid.bin -i esri.shp -i nasa.qi -i lidar.txt -iparse xyzti -iskip 2 (on-the-fly from ASCII) -i lidar.txt -iparse xyzi -itranslate_intensity 1024 -lof file_list.txt -stdin (pipe from stdin) -rescale 0.01 0.01 0.001 -rescale_xy 0.01 0.01 -rescale_z 0.01 -reoffset 600000 4000000 0 Fast AOI Queries for LAS/LAZ with spatial indexing LAX files -inside min_x min_y max_x max_y -inside_tile ll_x ll_y size -inside_circle center_x center_y radius Supported LAS Outputs -o lidar.las -o lidar.laz -o xyzta.txt -oparse xyzta (on-the-fly to ASCII) -o terrasolid.bin -o nasa.qi -odir C:\data\ground (specify output directory) -odix _classified (specify file name appendix) -ocut 2 (cut the last two characters from name) -olas -olaz -otxt -obin -oqfit (specify format) -stdout (pipe to stdout) -nil (pipe to NULL) LAStools (by info@rapidlasso.de) version 171215 (academic) usage: lastrack -i in.laz -track tj.laz -offset -2.21 -classify_below -0.4 7 -o out.laz lastrack -i in.laz -track tj.laz -offset -1.87 -drop_below -2.00 -o out.laz -verbose lastrack -i *.laz -track tj.laz -offset -2.07 -classify_between -0.4 0.5 2 -classify_between 3.5 10.5 25 -odir classed -olaz lastrack -i t028\*.laz -track tj28.laz -offset -1.92 -replace_z -odix _norm -olaz lastrack -i traj1\*.laz -track traj1.laz -classify_xy_range_between 0 4 7 -odix _denoised -olaz lastrack -version lastrack -h --------------- if you find bugs let me (info@rapidlasso.de) know.