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🏛️ USDA PRIORITY 1 — INCREASING PRODUCTION & NEW USES

📸 Hyperspectral Imaging (HSI) Calculators

Professional vegetation indices and remote sensing tools for precision agriculture, crop health monitoring, and spectral analysis.

🛰️ USDA ARS & NASA — Spectral Index Reference Thresholds REFERENCE DATA
NDVI / NDRE / EVI thresholds auto-loaded
NDVI Thresholds (USDA ARS)
0.8–1.0 — Dense vegetation
0.6–0.8 — Healthy crop
0.4–0.6 — Moderate stress
0.2–0.4 — Severe stress
<0.2 — Bare/dead
NDRE Thresholds (NASA)
0.45+ — High N status
0.30–0.45 — Adequate N
0.20–0.30 — N deficiency
<0.20 — Severe deficiency
EVI Thresholds (MODIS)
0.6+ — Dense canopy
0.4–0.6 — Moderate canopy
0.2–0.4 — Sparse/stressed
<0.2 — Bare/low biomass
GNDVI / NDWI (ESA)
GNDVI 0.6+ — High chlorophyll
GNDVI 0.3–0.6 — Moderate
NDWI 0.3+ — High water content
NDWI <0 — Water stress
Sources: USDA ARS Remote Sensing Lab • NASA MODIS/VIIRS Land Products • ESA Sentinel-2 Vegetation Products • Rouse et al. (1974), Gitelson & Merzlyak (1994)

🌿 NDVI Calculator

Model SF6-S.001

Normalized Difference Vegetation Index for crop health and biomass.

🌱 NDRE Calculator

Model SF6-S.002

Normalized Difference Red Edge for nitrogen status and crop stress.

🍃 GNDVI Calculator

Model SF6-S.003

Green NDVI for chlorophyll content. More sensitive than NDVI mid-late season.

📈 Enhanced Vegetation Index (EVI)

Model SF6-S.004

EVI improves sensitivity in high biomass regions and reduces atmospheric and soil background influences using blue band correction.

Standard: 2.5
Red aerosol coefficient
Blue aerosol coefficient
Standard: 1.0

🔬 Soil-Adjusted Vegetation Index (SAVI)

Model SF6-S.005

SAVI minimizes soil brightness effects in areas with sparse vegetation using a soil brightness correction factor.

L adjusts for vegetation density. Standard: 0.5

💧 Crop Water Stress Index (CWSI)

Model SF6-S.006

Detect crop water stress using canopy-air temperature differential and vapor pressure deficit for irrigation scheduling.

Typical: -1 to -3°C for well-watered crops
Typical: 4-8°C for non-transpiring canopy

Why AgrStak 🌾 HSI?

Aligned with USDA Secretary Rollins' Priority #1: Increasing Production & New Uses. AgrStak's HSI calculators transform complex spectral analysis into practical vegetation indices and crop stress metrics for farmers, agronomists, and remote sensing professionals.

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