I have an Altum camera + DLS2 (same as RedEgde MX + one thermal) and used it 3 separate flights about 1 h apart of the same field between about 10am -1pm. I used the supplied calibration panel in each flight. Day was cloudless with very little humidity so ideal conditions. Sun irradiance was constant during flight as measured by a field spectrometer. Thus the main variable was the sun angle. Now I need to select a variant of the Pix4D mapper workflow to process the spectral data with and without DLS then compare each reflectance dataset. I can’t find info which processing option is preferred for Altum/RedEgde MX imagery aside from this:
Radiometric Processing and Calibration
Allows the users to calibrate and correct the image reflectance, taking the illumination and sensor influence into consideration. It is possible to choose the type of radiometric correction to be done:
- No correction : no radiometric correction will be done
- Camera only : corrections will be applied to the parameters that are written in the EXIF metadata and relate to the camera (vignetting, dark current, ISO, etc…): Camera radiometric correction specifications
- Camera and Sun Irradiance : corrections will be applied to the camera parameters (same as using the option Camera only) as well as for the sun irradiance information written in the XMP.Camera.Irradiance EXIF tag.
- Camera, Sun Irradiance and Sun angle : corrections will be applied to the camera parameters and the sun irradiance information (same as using the option Camera and Sun Irradiance) as well as to take into account the sun position. This option should only be chosen for flights that were done in clear sky conditions.
Which I found here:
Latest Pix4D Mapper has another option:
Camera, Sun Irradiance and Sun angle using DLS IMU
Which option is preferred for calculating scene reflectance? How can I determine if Pix4D has used the DLS data?