[purduephotog]

One thing to think of is a Friend or Foe discriminator. An IR diode (s) emitting a certain frequency or IR reflective tape could be applied to alliance members.

Any camera with IR sensitivity (literally, anything) can discriminate that. If it can't, yank off the IR cutoff filter and slap in a piece of opticast IR plastic. In fact there are some IR goggles out at Target that are 50$ or so and excellent for IR. Identify the frequency and you know if the thing you're looking at is a Friend or Foe.

Of course, this also brings up ECM type opportunities- an IR emitter with sonar to 'jam' recognition. But I digress....