The minimum sun elevation (also known as solar zenith angle) is currently set for 10 degrees. If a collection is made below this threshold the task will be marked as test. The limitation is currently in place due to the challenges that are faced when the sun is at a low angle. Imagery that is taken at low sun angle (Solar Zenith) can appear bluish in color and may not have the same reflectance values as products with a higher angle. This may be subject to change in the future, however this limitation is currently in place as we evaluate the Pelican fleet further. 

More information on our Pelican fleet can be found here.