Most fissuroids even glow brightly when you're close. In my experience, the one thing that costs the most time, is being distracted by rocks that are not worth any attention.Here are three tricks I have learned while mining to make finding fissure roids easier.
Turn on Night Vision - The highlight that Night Vision applies to objects makes the fissures on rocks stand out like a sore thumb at a distance. Will save you many limpets.
Don't look for glowing rocks that are close by - Fissure-roids will glow bright even at a great distance. Less desirable rocks will only slightly glow and then get brighter. So if you pulse and then you see a rock WAAAAAAY in the distance then there is a very good chance that it is what you are looking for.
Point yourself towards the planet - Getting turned around in a ring system is absurdly easy to do when you are floating around rocks looking for cracks. Always readjust your bearings after you look at a rock or get done mining. It prevents you from accidentally going back the way you came and scanning the same rocks twice by accident. The easiest way to do this is to always keep the planet in front of you or always to your left or right.
I usually glide barely above the ring in FA off, ring above my ship and constantly pinging and looking around via headlook.
But this still doesn't answer my question about what the pulse wave scanner actually does, other than giving us a gameplay mechanic for finding good rocks. I want the lore.