I found out that I can survey red anomalies without any offensive ships being present. No battle gets triggered, I just get the reward the same way I do with white anomalies. Here's a picture:
I am playing on the test branch, and the game I'm playing started a couple of patches ago (I don't exactly remember which patch). I thought I'd mention that in case that's relevant.
I also noticed that when I survey yellow anomalies after the battle takes place and I get the reward, I can still move my ships. This was the way it worked in GC3, but so far my experience in GC4 has been that surveying an anomaly is supposed to use up all your extra moves. I don't know if this is a bug, but I thought I'd mention it.