How to properly resample and merge two products

Thanks George. Yes, the problem is that the geographical extent of the two images is different. I cannot, however, use intersection operation because I need to keep the non-overlapping region also. For example, in product_1 has a value ‘a’ at a pixel and product_2 has a value ‘NaN’ at the corresponding pixel, I want the final image to have a value of ‘a’ at that pixel.

I guess then the question is if it is possible to artificially increase the geographical extent of an image by padding with NaN values.

Thanks again.