Another option is to make buoys.
Woooo, Unless you want to end up with several dots on your screen impossible to recognize, you need to remember to name waypoints and stuff because the remove Salvo tracker doesn't have a "location" but it tracks targets. I just did a quick and dirty setup to show you how hard it could be otherwise.
First just launched ready ordnance as you can see no target, then I added a waypoint (just general).
This is important especially when you have multiple search and destroy missions along with monitoring of Jump points and such. Reason? You may have to clean it up at some point, trust me.

Oh, don't be worried, you can remove the waypoints as well, doing that doesn't cancel the target on the salvo screen.
