I had thought that reflectance vaues could only be from 0-1, since it is the ratio of the incident to reflected radiation. However, I have a project where the red edge reflectance varies from 0-2.8.
The other 3 channels give realistic results - between 0 and 0.6. With ‘no correction,’ selected in the Radiometric Processing and Calibration section of the Index Calculator the raw values for each sensor all have similar mean, min. and max. values. With all other corrections the red edge values are significantly higher (3x) than the others and greater than one.
On subsequent flights, all four sensors have given values in the expected range.
Does anyone have any suggestion about why this might be the case and what might be the best way to fix the problem?