Nagoya airport noises: bird control?

Factual Questions
1

I recently flew out of Chubu Centrair International Airport, the main airport serving Nagoya, Japan. Killing time before my departure, I discovered a humungous outdoor/rooftop observation deck that put me on a level near the tops of the vertical stabilizers of planes parked at their gates, providing a commanding view of the entire airport ground. This airport has a single runway, and every couple of minutes, I heard a loud popping noise coming from the general direction of the far side of the runway. Sounded a bit like a car backfiring. Pretty sure it wasn’t any boats/ships, since the nearest one appeared to be at least a couple of miles away.

So what was that noise? Was it some sort of bird deterrent system that keeps birds from nesting/settling in the area? Something else?

2

I’m pretty sure you have it. Here’s an example of the equipment.

Problem is, birds habituate pretty quickly to simple harassment methods.

3

That one looks like an electronic unit that emits bird distress calls over a speaker system. The popping noises were more likely from a propane cannon or something similar, which is another type of bird deterrent frequently used in vineyards. You’re right that birds can become habituated which is why some of them emit different sequences of blasts at randomized times and it’s recommended that they periodically be moved around.