Vegetation reflectance curve — the defining feature of healthy vegetation is low red reflectance (chlorophyll absorbs red for photosynthesis) and high NIR reflectance (scattered by the spongy mesophyll leaf structure).
| Cover | NIR | Red | NIR/Red |
|---|---|---|---|
| Water | Low | Low | ~0.1 |
| Dry bare soil | High | High | ~1 |
| Healthy vegetation | Very high | Low | Very high |