Adrian Russell and ALMA Site Development Manager, Eduardo Donoso, discuss how the roads are being graded for the ALMA observatory.
The Chilean Altiplano isn't all that flat. Centuries of wind erosion have made it a bit lumpy. ALMA's telescopes must all be level when they are bolted down, and the desert drive to their pads must also be smooth. Here, you can see how the telescope site is being bulldozed to perfection.
But this is no ordinary road grader. Notice the two telescopes poking out of the front sides. These are talking to a computer that is controlling the shovel. The computer is using GPS signals to carve an exactly flat path as the bulldozer rolls along.