Terrestrial lidar data collected from one hectare of tropical rainforest in Réserve Naturelle des Nouragues

Title
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Terrestrial lidar data collected from one hectare of tropical rainforest in Réserve Naturelle des Nouragues

Overview
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Terrestrial lidar data were acquired from one hectare of intact old-growth tropical rainforest in Réserve Naturelle des Nouragues, French Guiana, during November 2015. This dataset contains: i) the raw lidar data, and ii) transformation matrices to rotate and translate each scan into the coordinate system of the first scan.

Forest geography and type
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These data were collected close to the Station des Nouragues (https://nouragues.cnrs.fr), from a long-term censused 1 ha forest stand (code: NOU-11 / Nouragues Petit Plateu 20H; dimensions: 100 m x 100 m; see http://rainfor.org and https://forestplots.net). The approximate coordinates of the site in the WGS-84 datum are 4.08, -52.68 degrees. The site is classified as moist, terra firme, pre-quaternary, lowland, mixed species, old-growth, intact tropical forest.

Acquisition
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These data were collected using a REIGL VZ-400 terrestrial laser scanner. Scans were acquired at 121 locations on a 10 m Cartesian grid cast across the 1 ha plot, with the first and last scan location at the plot 0 m, 0 m and 100 m, 100 m x,y coordinates respectively. An upright and tilt scan was acquired at each location to capture a complete sample of the scene. The angular step between sequentially fired pulses was 0.04 degrees, The laser pulse has a wavelength of 1550 nm, a beam divergence of 0.35 mrad, and the diameter of the pulse at emission is 7 mm. The instrument was in ‘High Speed Mode’ (pulse repetition rate: 300 kHz), ‘Near Range Activation’ was off (minimum measurements range: 1.5 m), and waveforms were not stored. 10 targets (cylinders) covered in retroreflective tape (diameter: 54 mm, length: 100 mm) were placed between locations for scan registration purposes. The scanner was mounted on a surveyor's tripod, and the height of the instrument above-ground varied between locations.

File format
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The lidar data are stored in the RXP data stream format developed by RIEGL (see http://riegl.com). The transformation matrices are stored in ASCII format.

Processing
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The transformation matrices were generated by registering scans via the targets using RIEGL RiSCAN Pro (v.2.1.2), which included use of the ‘Multi Station Adjustment’ module.

File directory and naming convention
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./
├───ScanPos001                          (Directory: contains individual scan data and auxiliary files)
├───ScanPosN/
├───ScanPos242/
│   ├───151115_192411.rxp             (File: measurement data steam)
│   ├───151115_192411.mon.rxp     (File: monitoring data steam)
├───matrix/                                   (Directory: contains the transformation matrices)
│   ├───001.dat                                 (File: ASCII 4x4 transformation matrix)
│   ├───N.dat
│   ├───020.dat

Authors
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A. Burt
M. Disney

Contact
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[e-mail]

Acknowledgements
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Collection of these data was funded by Natural Environment Research Council (NERC) grants NE/N00373X/1 and NE/J016926/1, and the CNRS Nouragues Travel Grants Program. We gratefully acknowledge Jéróme Chave and Blaise Tymen.

License
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These data are distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC BY 4.0).