=== versions ===
python 3.12.0 | laspy 2.7.0 | lazrs 0.8.2 | numpy 2.5.4 | scipy 1.18.1 | rasterio 1.5.2

=== STAC search ===
area of interest: 1000 m x 800 m centred on the Washington Monument
USGS_LPC_MD_VA_Sandy_NCR_2014_18SUJ324306_LAS_2015  points=18,237,018
USGS_LPC_MD_VA_Sandy_NCR_2014_18SUJ324305_LAS_2015  points=13,976,445
USGS_LPC_MD_VA_Sandy_NCR_2014_18SUJ322306_LAS_2015  points=16,107,898
USGS_LPC_MD_VA_Sandy_NCR_2014_18SUJ322305_LAS_2015  points=13,997,484

=== streaming COPC ===
LAS 1.4, point format 6, CRS: NAD83 / UTM zone 18N + NAVD88 height
18SUJ324306_LAS_2015: 0 points in the area of interest
18SUJ324305_LAS_2015: 0 points in the area of interest
18SUJ322306_LAS_2015: 2,705,087 points in the area of interest
18SUJ322305_LAS_2015: 3,449,342 points in the area of interest
streamed in 15.0 s
wrote data/national_mall.laz (27.3 MB)

=== laspy.read ===
points: 6,154,429
dimensions: ['X', 'Y', 'Z', 'intensity', 'return_number', 'number_of_returns', 'synthetic', 'key_point', 'withheld', 'overlap', 'scanner_channel', 'scan_direction_flag', 'edge_of_flight_line', 'classification', 'user_data', 'scan_angle', 'point_source_id', 'gps_time']
x 322978.06..323978.06  y 4306083.24..4306883.24  z -24.99..665.98
density: 7.7 points/m²

class     points   share   z p1..p99 (m)   name
    1    766,610   12.5%     -0.1..  39.6   Unclassified
    2  1,450,255   23.6%      0.7..  11.6   Ground
    9    116,136    1.9%     -0.7..  -0.5   Water
   10        251    0.0%     -0.7..   3.0   Ignored ground
   11         49    0.0%    -11.5..   6.7   Withheld
   17  1,699,769   27.6%     -0.6..  40.6   Overlap unclassified
   18  2,073,657   33.7%      1.2..  11.7   Overlap ground
   25     47,702    0.8%     -0.6..   2.5   Overlap water

points from pulses with more than one return: 25.5%
chunked pass agrees with laspy.read: True

=== statistical outlier removal ===
mean neighbour distance 0.52 m, limit 1.98 m, took 2.6 s
outliers: 11,726 (0.19%); of the 11 points above 200 m, 11 are outliers

=== rasterise to 1 m ===
DSM cells with no return: 1.1%
DTM cells with no ground point: 13.9%
gap filling: 25.0 s
DTM -8.4..13.3 m | DSM -17.6..180.5 m | height above ground max 168.2 m

=== canopy height model ===
cells more than 2 m above ground: 28.7%
  mostly multi-return (trees): 14.2% | mostly single-return (buildings, structures): 10.0%
tree canopy height: median 11.4 m, 95th percentile 20.5 m, max 78.7 m
canopy patches of 20 m² or more: 363
wrote output/dtm.tif, output/dsm.tif, output/chm.tif

=== Washington Monument ===
highest point within 10 m: z=180.52 m at 5.7 m from the centre (class 17, return 1 of 1)
ground 15–30 m from the centre: median z=11.91 m from 15,280 ground points
lidar height: 168.61 m (553.2 ft)
official height (NGS survey): 169.046 m; difference -0.44 m