Working with Multispectral Data in Pix4D and Third-Party Software

Part 1: Introduction to Vegetation Indices and Pix4D

By Jacob Nederend

MSc Candidate, Department of Plant Agriculture, University of Guelph, Guelph, ON, Canada

What is a vegetation index and why can’t I just use NDVI?

In the previous post, I provided a general overview of how to obtain high quality orthomosaics from your eBee’s raw imagery. For agricultural UAV mapping, the last step in that workflow is obtaining reflectance maps from which vegetation indices (VIs) can be calculated. There are numerous resources available online that explain how VIs exploit patterns in the reflectance of visible and near-infrared light, however, a brief definition is the mathematical transformation of at least two spectral bands to enhance the definition of vegetative cover. All of the multispectral sensors currently used for UAV mapping are broadband, with the exception of very expensive and specialized hyperspectral sensors that measure hundreds of narrow bands (<5nm). Since most VIs were developed from broadband [...]