The base radar is much too intolerant of sporadic contact loss. I have to toggle the alarm off with snd.radar_alarm to stop it yelling constantly after a certain point in story mode. Filtering by entity type has no effect on which types of entity trigger the alarm; it only affects which ones are visually displayed on the radar map.
The radar seems to “lose sight” of certain contacts/entities for a single sweep and then reacquire the same ones again on the very next sweep. Every single time this happens, it triggers an alarm as though it’s a new entity. At the maximum radar sweep speed from base upgrades, which is something like 2-3 Hz, my radar log is filled with the entity count going down and up by exactly one every few seconds at all times. If only the radar would persist lost entities for just a sweep or two before discarding them, it could stop doing that entirely and the radar alarm could be infinitely more useful.
It’s profoundly annoying.