Executive Summary
Sub-pixel spectral unmixing and radiative transfer modeling of forest canopy biophysical variables, quantifying Equivalent Water Thickness (EWT), chlorophyll red-edge inflection shifts, and selective timber harvesting disturbance.
Key Methodological Findings
1.20 µm and 1.65 µm liquid water absorption depth tracks physiological drought stress 14–21 days prior to visible foliar discoloration.
Red-edge inflection point (REIP) calculation detects early-stage pathogen infestation and sub-lethal crown decline.
Sub-pixel unmixing isolates fractional non-photosynthetic vegetation (NPV) identifying skid trails and selective harvest roads under dense canopy.
Physics & Inversion Methodology
Canopy radiative transfer inversion coupling PROSPECT-D leaf optical model with 4SAIL canopy architecture model, inverted using look-up tables (LUT) with regularised cost functions.
Diagnostic Spectral Windows
| Band Regime | Wavelength Range | Physical / Chemical Feature |
|---|---|---|
| NIR / SWIR-1 | 1.18 – 1.25 µm | Canopy foliar liquid water absorption dip |
| Red-Edge | 690 – 740 nm | Chlorophyll absorption red-edge slope inflection point |
| SWIR-2 | 2.10 – 2.30 µm | Non-photosynthetic vegetation (lignin & cellulose dry woody tissue) |
Citation & Digital Object Identifier (DOI)
@techreport{axine_the_spectral_advantage_in_forestry_2026,
author = {Axine Labs Research},
title = {The Spectral Advantage in Forestry},
institution = {Axine Labs Technical Whitepaper Series},
number = {4},
year = {2026},
doi = {pending (Zenodo, 2026)},
url = {https://axinelabs.com/papers/the-spectral-advantage-in-forestry}
}