With the advance of remote sensing, geographic information systems, and global positioning systems, precision agriculture technology is the key for better crop management.
Crops vary, even within the same field. Precision agriculture technology enables better identification, analysis, and management of this temporal and spatial in-field variability. Precision ag is all about reducing this variability through more focused and targeted efforts—efforts which should increase production by maintaining crop quality and quantity.
When talking about remote sensing in precision agriculture, we immediately think of sensors and vegetation indices. Vegetation or vegetative index is calculated using different spectral bands, usually depending on what type of plant stress you are trying to visualize.
Our dedicated software for agriculture—Pix4Dfields—comes with the most popular list of indices predefined: NDVI, NDRE, VARI, TGI, SIPI2, LCI, BNDVI, GNDVI. Each index has a different use and a different visual output.
Vegetation indices in Pix4Dfields: NDVI & NDRE
Normalized Difference Vegetation Index
In precision agriculture, NDVI is used to measure biomass. Whereas, in forestry, it is used to quantify forest supply and leaf area index.
NDRE – Normalized Difference Red Edge
Index sensitive to chlorophyll content in leaves against soil background effects. This index can only be formulated when the red edge band is available.
Vegetation indices in Pix4Dfields: SIPI2 & LCI
SIPI2 – Structure Intensive Pigment Index 2
Index used in areas with high variability in canopy structure (e.g. forestry).
LCI – Leaf Chlorophyll Index
Index to assess chlorophyll content in areas of complete leaf coverage.
Vegetation indices in Pix4Dfields: TGI & VARI
TGI – Triangular Greenness Index
RGB index for chlorophyll sensitivity. TGI index relies on reflectance values at visible wavelengths. It is a fairly good proxy for chlorophyll content in areas of high leaf cover.
VARI – Visible Atmospherically Resistant Index
RGB index for leaf coverage. This index is used to estimate the fraction of vegetation in an image with low sensitivity to atmospheric effects.
Vegetation indices in Pix4Dfields: BNDVI & GNDVI
BNDVI – Blue Normalized Difference Vegetation Index
BNDVI is an index without red channel availability that uses the visible blue, for areas sensitive to chlorophyll content.
GNDVI – Green Normalized Difference Vegetation Index
GNDVI index uses visible green instead of visible red and near infrared. Useful for measuring rates of photosynthesis and monitoring the plant stress.