There are a few spots for sniping and a glitch on Ragnarok that is explained in this video. This first one is the glitch and is only accessible if you use the banshee and you can get out of it with a little bit of practice with the jet pack. It allows you to get into the main structure. You can also get on top of some of the rocks on one side of the map which is an excellent spot for sniping. There are two of these spots.