Hmm, compare a pen size laser pointer designed to point at something vs a MTHEL that in best case fits in the largest avaliable truck, designed to destroy incoming missiles...or a hand held police speed-radar gun vs AWAC.
This analogue is flawed, they have different goal and purpose.
Both satellite and plane mounted IR detectors will want to be as sensitive as possible, in order to detect at as far range as possible.
This leaves it up to how large is the detector, and what obstacles in their respective environment.
Obstacles such as cloud cover in the observed atmosphere, and the fraction of ultra-high energy cosmic ray events that may be expected to occur in volumes of the viewed atmosphere non-obscured by clouds, and last but not least, background, sky or ground.
It is unrealistic that one of these systems is 1000 times better then the other.
30%, at best, either way, sounds more reasonable.