HiGLASS-LS20: First Gap-free 20 m 5-Day LAI/FAPAR Products over China (2018–2024)
1. Overview
HiGLASS-LS20 is the first gap-free, 20-meter resolution, 5-day LAI (Leaf Area Index) and FAPAR (Fraction of Absorbed Photosynthetically Active Radiation) product over China, derived from integrated Landsat-8/9 and Sentinel-2 Analysis Ready Data (ARD). The product spans 2018–2024 and provides consistent, high-resolution vegetation dynamics for ecological monitoring, agriculture, carbon and water cycle studies.

2. File Naming Convention
HiGLASS_LS20_[lat][lon]_[year]_v01_LAI.tif
HiGLASS_LS20_[lat][lon]_[year]_v01_FAPAR.tif
Each tile is  1° × 1° in geographic coordinates (WGS84).
Tile centre = integer degree + 0.5° (i.e. a tile named n018e108 is centred at 18.5°N, 108.5°E and spans approximately 18°N–19°N, 108°E–109°E).
Each file contains 73 bands, corresponding to 5-day composites: DOY 001, 006, 011, …, 361 (Jan 1, Jan 6, Jan 11, ..., Dec 22)

3. Data Format: GeoTIFF (.tif)
Projection: Geographic (Lat/Lon), EPSG:4326
Spatial resolution: ~20 m
Temporal resolution: 5-day composites (73 per year)
Data type: uint8

4. Scale
LAI Scale factor: 0.1
Physical range: 0 – 10.0
Unit: m² m⁻²

FAPAR Scale factor: 0.004
Physical range: 0 – 1.0
Unit: – (unitless)

LAI    = band_value × 0.1
FAPAR  = band_value × 0.004

5. Generate HiGLASS-LS20 for Other Regions beyond China (2019–2024)
To produce the Hi-GLASS-LS20 LAI/FAPAR product for any region worldwide and for the years 2019–2024, run the open-source pipeline in Google Colab:
https://colab.research.google.com/drive/1zGYbUkh4COoZqpWA2tfMLZHVfsGZ1nAo?usp=sharing

6. When using this dataset, please cite:
Ma, H., Q. Wang, W. Li, Y. Chen, J. Xu, Y. Ma, J. Huang, and S. Liang (2025).
“The first gap-free 20 m 5-day LAI/FAPAR products over China (2018–2023) from integrated Landsat-8/9 and Sentinel-2 Analysis Ready Data.”
Remote Sensing of Environment, 331, 115048.DOI: 10.1016/j.rse.2025.115048
Full text: https://www.sciencedirect.com/science/article/pii/S0034425725004523

If you encounter any issue, feel free to contact Dr. Han Ma via mahan@hku.hk.