I've seen this stunt performed and landed on the lower ledge, but I've been trying to get onto the high ledge with the same bump. I've gotten so close (my back tire landed on the ledge, and I didn't realise I was actually on the ledge itself and I fell off) but I've decided to let you guys have a whack at it. I'm not great at stunting.
Picture's attatched at the bottom. Enjoy.