wiki:las_support

Version 1 (modified by dburken, 14 years ago) ( diff )

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LAS LIDAR Support

Two plugins available with LAS readers:

liblas plugin: http://trac.osgeo.org/ossim/browser/trunk/ossim_plugins/liblas

Generic las plugin: http://trac.osgeo.org/ossim/browser/trunk/ossim_plugins/las

The liblas plugin has a dependency on libLAS. http://liblas.org/

The las plugin has no dependencies other than ossim. Currently only coded for point type one.

The is a generic LAS header dump in ossim core so you can do ossim-info -d without any plugin.

With either plugin you can do:

$ ossim-info -d -i -p 000330.las 
las.file_source_id: 0
las.gps_time_type: 0
las.waveform_data_packets_internal: 0
las.waveform_data_packets_external: 0
las.synthetically_generated: 0
las.project_id_guid: 1dee478d-fa50-49c8-a9c54fde367ace40
las.version: 1.2
las.system_indentifier: NIIRS10
las.generating_software: LIDAR1 tiled
las.file_creation_day: 250
las.file_creation_year: 2010
las.header_size: 227
las.offset_to_point_data: 1966
las.number_of_variable_length_records: 5
las.point_data_format_id: 1
las.point_data_record_length: 28
las.number_of_point_records: 2915929
las.number_of_points_return1: 2596564
las.number_of_points_return2: 269269
las.number_of_points_return3: 47603
las.number_of_points_return4: 2493
las.number_of_points_return5: 0
las.x_scale_factor: 0.0100
las.y_scale_factor: 0.0100
las.z_scale_factor: 0.0100
las.x_offset: 0.0000
las.y_offset: 0.0000
las.z_offset: 0.0000
las.max_x: 13005001.3200
las.min_x: 13000001.3300
las.max_y: 335000.1200
las.min_y: 330000.1200
las.max_z: 1580.3900
las.min_z: 926.7200
image0.decimal_degrees_per_pixel_lat:  9.00281717218119e-06
image0.decimal_degrees_per_pixel_lon:  1.2150363478007e-05
image0.decimations:  (1,1) (0.5,0.5) (0.25,0.25) (0.125,0.125) (0.0625,0.0625) (0.03125,0.03125) (0.015625,0.015625) (0.0078125,0.0078125)
image0.gsd:  (1.00005919045009,1.00005919171835)
image0.image_size:  (1524,1524)
image0.ll_lat:  42.4046185000387
image0.ll_lon:  -84.8235731136942
image0.lr_lat:  42.4046914040585
image0.lr_lon:  -84.8050721763752
image0.meters_per_pixel_x:  1.00005919045009
image0.meters_per_pixel_y:  1.00005919171835
image0.projection.central_meridian:  -84.3666666666667
image0.projection.datum:  NAR
image0.projection.elevation_lookup_flag:  0
image0.projection.ellipse_code:  RF
image0.projection.ellipse_epsg_code:  7019
image0.projection.ellipse_name:  GRS 80
image0.projection.false_easting_northing:  (4000012.32,0)
image0.projection.false_easting_northing_units:  feet
image0.projection.gcs_code:  4152
image0.projection.major_axis:  6378137
image0.projection.minor_axis:  6356752.3141
image0.projection.origin_latitude:  41.5
image0.projection.pcs_code:  2898
image0.projection.pixel_scale_units:  meters
image0.projection.pixel_scale_xy:  (1,1)
image0.projection.srs_name:  EPSG:2898
image0.projection.std_parallel_1:  42.1
image0.projection.std_parallel_2:  43.6667
image0.projection.tie_point_units:  meters
image0.projection.tie_point_xy:  (3962400.405384,102108.036576)
image0.projection.type:  ossimLambertConformalConicProjection
image0.target_rrds:  0
image0.tie_point_lat:  42.418329790592
image0.tie_point_lon:  -84.8236735393142
image0.type:  ossimImageGeometry
image0.ul_lat:  42.418329790592
image0.ul_lon:  -84.8236735393142
image0.ur_lat:  42.4184027106036
image0.ur_lon:  -84.8051685357372

To convert a LAS file to a geotiff:

ossim-icp tiff_tiled_band_separate 000335.las outputs/t1.tif

To convert a LAS file to a geotiff setting the scale (grid size) to 2.5 meters:

ossim-icp --reader-prop scale=2.5 tiff_tiled_band_separate 000335.las outputs/t1.tif
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