Calculating vegetation indexes with GDAL raster calculator?

Question

I want to calculate a few of vegetation indexes [ example: NDPI (red band-green band)/(red band + green band)] in a model with the GDAL raster calculator but I don't know how put the equation here:

Answer 1

You need to assign band designations based on the information provided by the sensor manufacturer.

For example, if you are using landsat data, you can find them here: https://www.usgs.gov/faqs/what-are-band-designations-landsat-satellites?qt-news_science_products=0#qt-news_science_products.

Set your bands as A, B, C, D, etc.., taking note of which is which. Then you can construct algebraic expressions such as @S_Carter suggested in the window you have circled.

Answer 2

Make the A raster your red band, the B raster your green band.

(A-B)/(A+B). This link covers a how-to using a different index, but the process is the same.