| RVI Algorithm Specification | |
The Ratio Vegetation Index algorithm is the simplest ratio-based one.
The simplest ratio-based index is also called the Simple Ratio (SR):
- High for vegetation
- Low for soil, ice, water, etc.
- Indicates amount of vegetation
- Reduces the effects of atmosphere and topography
The RVI results from the following equation:
RVI = (IR_factor * near_IR) / (red_factor * red)
This is the most widely calculated vegetation index, although you rarely hear of it as a vegetation index.
A common practice in remote sensing is the use of band ratios (e.g. the ratio of NIR to RED) to eliminate various effects such as:
- irradiance (topography)
- transmittance (atmospheric effects)
Also the processor computes an additional flags band called 'rvi_flags' with the following bit coding:
| Bit Position | Description |
|---|---|
| Bit 0 | The computed value for RVI is NAN or is Infinite |
| Bit 1 | The computed value for RVI is less than 0 (zero) |
| Bit 2 | The computed value for RVI is greater than Infinity |