NDVI, NDRE, GNDVI, EVI, SAVI, and CWSI remote sensing indices — precision vegetation health scoring grounded in USDA ARS and NASA remote sensing research standards.
Live USDA NASS crop yields and prices by state and year. Provides real-world yield context for interpreting spectral stress index outputs from SF6 calculators.
Source: USDA NASS QuickStats API — Crop yield & price survey data
USDA NASS Cropland Data Layer — planted acreage by crop type and state. Provides land cover context for spectral index analysis and crop identification from satellite imagery.
USDA NASS VegScape weekly NDVI and vegetation condition data from MODIS satellite imagery. Provides national and state-level NDVI anomaly benchmarks to contextualize field-level spectral index readings.
Model SF6-S.001
Normalized Difference Vegetation Index for crop health and biomass.
Model SF6-S.002
Normalized Difference Red Edge for nitrogen status and crop stress.
Model SF6-S.003
Green NDVI for chlorophyll content. More sensitive than NDVI mid-late season.
Model SF6-S.004
EVI improves sensitivity in high biomass regions and reduces atmospheric and soil background influences using blue band correction.
Model SF6-S.005
SAVI minimizes soil brightness effects in areas with sparse vegetation using a soil brightness correction factor.
Model SF6-S.006
Detect crop water stress using canopy-air temperature differential and vapor pressure deficit for irrigation scheduling.
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.