How would I make an IR beacon system
Consider these receiver "phototransistors". They automatically decode a 38 kHz signal, which is what most remote controls use. Because it is pulsing it is virtually immune to ambient IR light including sunlight, although there is a limit as to how much ambient light they can reject. There are plenty of code examples and projects on the net which send out 38 kHz signals to control TVs, DVD players, etc. but the idea is applicable to IR beacons; just choose a code/sequence which won't interfere with other products.