prefire<- "LC80010852017008LGN00" 	# assigns 'LC80010852017008LGN00' as 'prefire' in R 
postfire<- "LC80010852017056LGN00" 	# assigns 'LC80010852017056LGN00' as 'postfire' in R

lspre<- ReadLandsat8(prefire) 		# reads all images pre-fire
lspost<- ReadLandsat8(postfire) 	# reads all images post-fire