The RedEdge Downwelling Light Sensor (DLS) is used in conjunction with MicaSense's Calibrated Reflectance Panel (CRP) to enable improved reflectance calibrations in situations where ambient light conditions are changing in the middle of a flight.
The DLS is intended to be installed on top of the aircraft, facing up towards the sky. It records data on the amount of light from the sky for each of the 5 bands of the RedEdge camera, and captures this data throughout the flight (embedded within the metadata of each image for each band). In post processing, data from the DLS and the CRP can be used to correct for changing illumination conditions during flight.
We are continually making improvements to the DLS itself, as well as the workflow in which we incorporate DLS data into Atlas outputs. As we do that, we expect that the need for CRP images will lessen. However at this time, we recommend using the CRP in conjunction with the DLS. Please reference the instructions for taking proper images of the CRP listed on the inside of the CRP case. Please also reference the DLS integration guide when installing the DLS.