This dataset contains Aerial LiDAR (also known as airborne laser scanning, ALS) data in .las format collected over tropical forests in Nouragues in French Guiana in 2019. The data were collected by Altoa using a BN2 aircraft flying at approximately 900 m altitude at a speed of approximately 180 km/hr. Trajectory files in txt format giving detailed flight data are included with the archived dataset. The LiDAR instrument was RIEGL LMS-Q780 and used a minimum pulse density of 15 points/sqm. The lateral overlap between two flight lines was 80%. with a Scan angle of +/- 30 degrees. The data coordinate reference system used with the data files is epsg 2972 more details of this and of the Nouragues site can be found in the documentation section.

This dataset contains Aerial LiDAR (also known as airborne laser scanning, ALS) data in .las format collected over tropical forests in Paracou in French Guiana in 2019. The data were collected by Altoa using a BN2 aircraft flying at approximately 900 m altitude at a speed of approximately 180 km/hr. Trajectory files in txt format giving detailed flight data are included with the archived dataset. The LiDAR instrume was a RIEGL LMS-Q780 and used a minimum pulse density of 15 points/sqm. The lateral overlap between two flight lines was 80% with a scan angle of +/- 30 degrees. The data coordinate reference system used with the data files is epsg 2972 more details of this and of the Paracou site can be found in the documentation section.

Terrestrial laser scanning (TLS) was conducted at three ForestScan 1ha (100m x 100m) Forest Biomass Reference Measurement Site (FBRMS) plots in French Guiana from September to October 2022 by Cecilia Chavana-Bryant using a Riegl VZ-400i scanner. Data collection assistance was provided by UCL PhD student Wanxin Yang and a local team of field assistants, data processing assistance was provided by Mr Peter Vines. This data collection was part of the European Space Agency (ESA) funded ForestScan project designed to improve the use of new Earth Observation (EO) estimates of above ground biomass (AGB) by providing terrestial (TLS), unpiloted airborne vehicles (UAV-LS)- and airborne (ALS) LiDAR scanning-derived AGB and tree census data to compare to allometric and EO-derived estimates. Scans were acquired using chain sampling at 121 locations along a 10m Cartesian grid to ensure sufficient data overlap to produce high-quality point clouds for all ForestScan 1ha FBRMS plots. Due to the scanner's 100° field of view, capturing a complete sample of the scene at each scan location required two scans -an upright scan and a tilt scan. Upright scans are odd-numbered while tilt scans are even-numbered. The first scan at each plot is collected at the southwest corner, i.e. scan position 0,0 (unless something impedes it, e.g. stream, large tree fall, etc. or if the plot is oriented differently). To facilitate scan registration, five retro-reflective targets were located between scan positions with all tilt scans along the first sampling line were oriented towards the same sampling position along the next sampling line and tilt scans at the ends of sampling lines (i.e. tilt scans along plot edges) were oriented towards the inside of the plot. This aids scan registration as it allows tilt scans to capture the previous scan location within its field of view. A total of 242 scans were collected at each plot. The Riegl operating and processing software RiSCAN PRO version 2.14.1 was used to generate a plot-level point cloud, scans were coarse registered using the shared retro-reflective targets located between consecutive scan positions. Coarse registration was then fine-tuned using Multi Station Adjustment 2 (MSA2). Data for each of the three FBRMS plots is found within plot directories: FG5c1, FG6c2 and FG8c4. Plot directories contain a main project directory (named using the starting date of data collection, e.g. 2022-10-10_FG5c1.PROJ) with nine data subdirectories and a tile_index.dat file as shown in the archived document /neodc/forestscan/data/french_guiana/paracou/TLS_Plot_FG5c1/ForestScan_example_data_directory_structure.pdf which details the data structure shared by all FBRSM plot TLS datasets.

This collection is part of the European Space Agency (ESA) funded ForestScan project designed to improve the use of new Earth Observation (EO) estimates of above ground biomass (AGB) by providing TLS-, unmanned airborne vehicles (UAV-LS)- and airborne (ALS) LiDAR scanning-derived AGB and tree census data to compare to allometric and EO-derived estimates. The collection contains a multiscale dataset of tropical forest 3D structural measurements, including terrestrial laser scanning (TLS), unoccupied aerial vehicle LiDAR scanning (UAV-LS), airborne laser scanning (ALS), and in-situ tree census and ancillary data. ForestScan was conceived to evaluate new technologies for characterising forest structure and biomass at Forest Biomass Reference Measurement Sites (FBRMS). These data are critical for the calibration and validation of earth observation (EO) estimates of forest biomass, as well as providing broader insights into tropical forest structure. Data are presented for the first three Forest Biomass Research Monitoring Sites in Paracou Research Station in French Guiana; Station d'Etudes des Gorilles et Chimpanzes, Lopé National Park in Gabon; and Kabili-Sepilok Forest Reserve, Malaysia. Field data for each site include new 3D LiDAR measurements combined with plot tree census and ancillary data, unmanned aerial vehicle-based laser scanning (UAV-LS) and airborne laser scanning (ALS) where possible, at a multi-hectare scale. Not all data types were collected at all sites, reflecting the practical challenges of field data collection. We also provide detailed field data collection protocols for TLS, UAV-LS, and ALS measurements for each site, along with requirements for ancillary data to enable integration with ALS data (where possible) and upscaling to EO estimates. The ForestScan project is closely aligned with other international initiatives, particularly the Committee on Earth Observation Satellites (CEOS) Working Group on Calibration & Validation (WGCV) AGB cal/val protocols, and GEO-TREES, a new Group on Earth Observations (GEO) initiative aimed at establishing a network of FBRM sites. ForestScan is the first demonstration of what could be achieved more broadly under GEO-TREES, which would significantly expand and enhance the use of EO-derived AGB estimates