The calculation of the Normalized Vegetation Index (NDVI) to analyze remote sensing measurements was first reported in 1973. My question is, why has NDVI gotten all the attention? Don’t get me wrong I think NDVI is an amazing tool, but why has it been the index to rise to the top since it is a relatively old concept? With the development of different approaches to characterize vegetation as the calculations of Leaf Area Index (LAI), leaf chlorophyll content, background soil reflectance, and canopy shadows, there should be more indicators of a healthy crop beyond the traditional NDVI. For example, an important distinct parameter in the method of precision agriculture is the chlorophyll content, a direct indicator of photosynthesis activity, which is in turn related to nitrogen concentration in vegetation. Therefore, a good estimation of chlorophyll content serves as a means to calculate the crop response to nitrogen application.
In searching for estimations derived from the use of aerial imaginary that will help the farmer out to make valuable decisions, I think there would be great information gotten from the calculations of the Green Normalized Vegetation Index (GNDVI) or the Chlorophyll Vegetation Index (CVI) for nitrogen prediction. How about the calculation of the Modified Chlorophyll Absorption Ratio Index (MCARI2)? It can help to obtain a better estimation of the leaf area index of vegetation areas where NDVI gets saturated. There are lots of vegetation indexes that are great tools and with the arrival of three band filters, a bunch of other calculations of vegetation indices could come to light as great aids for crop management. Next is a link to a paper (Integrated narrow-band vegetation indices for prediction of crop chlorophyll content for application to precision agriculture) written back in 2001 that puts significant importance to nitrogen calculation for precision agriculture: http://quantalab.ias.csic.es/pdf/paper_RSE_driss.pdf
There is not much for software out there right now that will calculate other indexes. We are currently working on a software tool here at Aero Hawk that will calculate a plethora of vegetation indexes. With triple band filters coming to market it is a must, and we think we are on a bleeding edge of getting it right for the Ag Industry.