Once we have installed the soilspec package we need some data (spectra) to work with, so we can import our own data, or to use the data available in the package (datsoilspc).
The data set has 391 spectra samples (range from 350 to 2500 nm in 1 nm steps) acquired with an AgriSpec instrument using a probe. All the information of this dataset is given in the description of this file in the poject.
Once we have the data in the workspace we can plot it as a first and quick look, so we realize that we must treat these spectra in order to have a better idea of the characteristics of the samples.
The spectra come with four constituent values: clay, sand, silt and Total Carbon.
The package come with another data set with spectra of a profile with factor variables for the Horizon ("H1", "H2", "H3"), Soil ("A", "B" , "C" and "D") and the reflectance spectra scanned every 10cm down to the profile (see the file description in the package).
Before to work with the spectra in the coming posts, I show some videos to understand what a profile is, and how the colour can talk about the characteristics of the soil.
In the next video professor Ray Weil study the colour in a profile.
Can we use spectroscopy to predict a colour (based on the spectrum) and to compare the predicted value with the original colour?. I think this a good exercise that the author of the soil package propose in the book "Soil Spectral Inference with R" which is the companion book for this package.
