I did some searching and hadn't found this before. The rules to me seemed clear that Jump only allowed moving over terrain and didn't allow me to jump over ATRTs, but I thought I would ask the question:

Rules Question: Can Luke use jump to move over ATRTs or other vehicles shorter than height 1?
Alex Davy: Yep, he can.

I'm not sure I've ever been more pleased to be wrong!

Huh...well okay then. Guess you can use an AT-RT as mobile light cover for Luke after all.

That's directly against RAW, is it not? Vehicles are not terrain...

Well it seems to be clear that the intent is jump allows a mini to go over all obstacles. Not written into the rules, though ?