I'm working with a satellite (SMAP) that has a temporal resolution of 3 days. So every day the sensor covers a portion of Brazil. I have the Geotiff files, but I need to calculate the mean values for the three images, but the mean will be calculated only for the pixels that overlap. In the end, I need a single image for the period of three days.
How can I do this?
In this link there is a file that contains the three images.
Here an example of one of these images: