Correct, Lightning mounted Redtops had a front-hemisphere capability. IR acquisition for launch needed a bit more 'oomph' than would be available from 'supersonic flight effects'. Dependent on closing speed, we are talking several miles range at launch. A quick burst of burner from the 'target' was always required for training. Jindi flare was excellent of course!
Redtop was also carried by the Sea Vixen, not totally sure after all this time if they had a true front-hemisphere capability, possibly only high angle-off. Step-in a Sea Vixen man please.
lm