Breadcrumb: Which way's north?

The description of the tabernacle and courtyard use specific directions. Instead of saying that a wall was for the long or short side of the tabernacle, it notes that it was for the southern, northern, western, or eastern side. (Ex. 36:23-30; Ex. 38:9-15) Given that the tabernacle was meant to be transported with the Israelites as they travelled, it seems odd that sides should be designated by cardinal direction. On the other hand, we have established that God was a stickler for details, and this was probably just another instructions the Israelites needed to comply with.