Checking LiDAR data with LASTools

You can find out about the contents of a LiDAR data file with the lasinfo.exe tool.

• Open the Windows command prompt:Win + X then Command prompt
• Navigate to the project folder: CD C:\GossanHill
• We’ll work with these files:

29/03/2017  04:19 PM           999,424 lasinfo.exe
30/03/2017  08:45 PM     1,107,238,731 Merged12.las

• Enter a command like this: las2las Merged12.las
• You’ll see output like this:

lasinfo (170313) report for Merged12.las
reporting all LAS header entries:
  file signature:             'LASF'
  file source ID:             0
  global_encoding:            16
  project ID GUID data 1-4:   00000000-0000-0000-0000-000000000000
  version major.minor:        1.2
  system identifier:          'LAStools (c) by rapidlasso GmbH'
  generating software:        'las2las (version 170313)'
  file creation day/year:     53/2016
  header size:                227
  offset to point data:       935
  number var. length records: 1
  point data format:          1
  point data record length:   28
  number of point records:    39544207
  number of points by return: 29157767 7543334 2398550 405487 36970
  scale factor x y z:         0.01 0.01 0.01
  offset x y z:               0 0 0
  min x y z:                  688600.00 6096750.00 511.71
  max x y z:                  690324.99 6098199.99 700.25
variable length header record 1 of 1:
  reserved             0
  user ID              'LASF_Projection'
  record ID            2112
  length after header  654
  description          'OGC WKT'
    WKT OGC COORDINATE SYSTEM:
    PROJCS["GDA94 / MGA zone 55",GEOGCS["GDA94",DATUM["Geocentric_Datum_of_Australia_1994",SPHEROID["GRS 1980",6378137,298.257222101,AUTHORITY["EPSG","7019"]],TOWGS84[0,0,0,0,0,0,0],AUTHORITY["EPSG","6283"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.01745329251994328,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4283"]],UNIT["metre",1,AUTHORITY["EPSG","9001"]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",147],PARAMETER["scale_factor",0.9996],PARAMETER["false_easting",500000],PARAMETER["false_northing",10000000],AUTHORITY["EPSG","28355"],AXIS["Easting",EAST],AXIS["Northing",NORTH]]
reporting minimum and maximum for all LAS point record entries ...
  X            68860000   69032499
  Y           609675000  609819999
  Z               51171      70025
  intensity           1      65535
  return_number       1          7
  number_of_returns   1          7
  edge_of_flight_line 0          1
  scan_direction_flag 1          1
  classification      1         18
  scan_angle_rank   -30         30
  user_data           0          0
  point_source_ID   580        588
  gps_time 363598.400587 365928.475851
number of first returns:        29157767
number of intermediate returns: 2846655
number of last returns:         29145045
number of single returns:       21605260
WARNING: there are 2006 points with return number 6
WARNING: there are 93 points with return number 7
overview over number of returns of given pulse: 21605260 10290843 5985117 1475896 174959 11503 629
histogram of classification of points:
            1509  unclassified (1)
        10902051  ground (2)
        11246018  low vegetation (3)
         2590372  medium vegetation (4)
        11714840  high vegetation (5)
         3077342  building (6)
            4107  noise (7)
             972  water (9)
            6772  bridge deck (17)
             224  Reserved for ASPRS Definition (18)

Some of the most useful information there includes:

• The number of data points: ~39.5 million
• The co-ordinates covered: from (688600.00, 6096750.00) in the south-west to (690324.99, 6098199.99) in the north-east
• Counts of points by classification
• The file format: Version 1.2

This article is part of the Orienteering Mapping with LiDAR, Smartphones and Free Tools series.

Polite and constructive responses are always welcome.