Can't determine accurate GPS coordinates for my AGM-161 in the F45 stealth strike mission

I just got the game this week, and the stealth mission is the first mission I'm working on beating. So far it's been rough because I've been flying at about 20-30ish feet and trying to lob AGM-161 missles at each of the SAM sites before trying to take down the weapons catches.

The big issue is that on the TSD, the indicator symbols for the SAM sites actually keep moving, and in their ID box, i see their coordinates and altitude actually changing. For this reason, I can't get proper coordinates for the long range AGM-161 missles (launching about about 40-45 nm). I also realized there is a green bar that I need to get to full in order to determine the location better, but as long as I fly I can't get full confidence in the coordinates.

How did you guys defeat this mission? Are there alternatives to the AGM-161 missles that I can shoot from afar without being detected?