I have 1 nightlight image of DMSP/OLS. It is uncalibrated. I want to calibrate the image based on Wu's (2013) methodology. Every time I try to run the command "i.nightlights.intercalibration" on GRASS GIS (v. 7.4) I get that error "no data base element found".
Why is that?
I have made every step of Wu's methodology.