Frequently Asked Question

What is OSAVI

OSAVI (Optimized Soil-Adjusted Vegetation Index)

      Uses

  • differentiate soil pixels 
  • related to LAI at some levels where NDVI saturates
  • accounts for non-linear interactions of light between soil and vegetation 
  • used as a structural index for some combined indices designed for chlorophyll detection

 

Description

OSAVI maps variability in canopy density. In addition, it is not sensitive to soil brightness (when different soil types are present). It is robust to variability in soil brightness and has enhanced sensitivity to vegetation cover greater than 50%. This index is best used in areas with relatively sparse vegetation where soil is visible through the canopy and where NDVI saturates (high plant density).

OSAVI is a special case of the Soil Adjusted Vegetation Index (SAVI). OSAVI was developed by Rondeaux et al. in 1996 using the reflectance in the near-infrared (nir) and red (r) bands with an optimized soil adjustment coefficient. The soil adjustment coefficient (0.16) was selected as the optimal value to minimize NDVI's sensitivity to variation in soil background under a wide range of environmental conditions. OSAVI is a hybrid between ratio-based indices such as NDVI and orthogonal indices such as PVI. SAVI has a default soil-adjustment factor of 0.5; however, it is recommended to use 0.16 as implemented in OSAVI. Like any normalized difference index, OSAVI values can range from -1 to 1. High OSAVI values indicate denser, healthier vegetation whereas lower values indicate less vigor.

 

© Information courtesy of http://micasense.com