Big Bark Trophy in Archangel

You can get this one on the second mission. Some big ships will fly in and you have to shoot their rockets, one of your squad will mention having a big bomb ready, and when they deploy it you just shoot it. I wasn't even attempting to get this trophy the so I think this should be pretty easy to get if you just don't miss the bomb. If you wait for some of the screechers to be near the bomb it should be pretty easy.

unless i'm mistaken this is tying more into the 4th mission rather than the 2nd where bulldog (one of your allies) launches a bomb (looks like a yellow ocean mine) and you can shoot it to destroy the enemies around you (the carrier like ships + the smaller ones)