Abstract

PAZ-PELLAT, Fernando; REYES, Marisol  and  MEDIANO, Edgardo. Design of spectral vegetation indexes using iso-soil curves. Agrociencia [online]. 2011, vol.45, n.1, pp.121-134. ISSN 2521-9766.

The design of spectral vegetation indexes (VI) based on the lines iso-leaf area index (same amount of vegetation and different optical properties of the soils under the vegetation) in two bands of the electromagnetic spectrum, the red (R) and near-infrared (NIR), is complicated because of the expolinear pattern with change of slope, among the parameters that define these lines. An alternative design is to consider the patterns of iso-soil curves (same soil, and varying amounts of vegetation), using the NIR as a saturation band as slow as possible. The introduced index ISVI (VI based on the iso-soil curves) allows this type of approach, by using a transformation of the space of R to make it coincide with the soil line and a mathematical structure similar to uni-band spectral indexes. ISVI validation using radiative simulations and crop experiments produced acceptable results, particularly with a perspective of minimizing the soil effect at píxel by píxel scale. The transformation of the ISVI allows parameterization of the growth curve in a linear format, simple to implement in algorithmic terms.

Keywords : ISVI; iso-soil curves; uni-band indexes; soil effect; parametric curve of growth.