Hi Andreas,
I would be interested to take a closer look into this paper. Is there a link where I can download this?
From my point of view, deriving reliable values for vegetation indizes from NIR-converted consumer-grade cameras is not at all an easy task, as often is suggested.
The concept of vegetation indizes was originally developed using multispectral sensors (for example Landsat Multispectralscanner MSS or Landsat Thematic Mapper TM) with well defined imaging parameters and spectral characteristics. Furthermore there is additional information recorded during imaging which enables us to do a radiometric calibration - and if necessary, to correct also for atmospheric effects. Otherwise the image data and derived data such as VI will hardly be comparable between different acquisition dates and between different sensors.
The question I have in mind is, how much effort is necessary to get radiometrically calibrated measurements for the wavelength of interest from consumer-grade camaras, in order to derive comparable values for vegetation indizes - comparable over time and comparable between different sensors / consumer-grade cameras?
kind regards