[toomuchtodo]

Yes, because jamming GNSS in those countries incurs penalties from RF regulators (broadly speaking). Consider the power output required in order to impact gps accuracy at airliner cruising altitude (~9-10km above ground level). Your RF emissions will not go unnoticed by those responsible for ensuring RF hygiene within their jurisdiction.

[teruakohatu]

I think I misinterpreted the map. So "low interference" on this map means "probably no interference" not "low levels of jamming"?

Because i agree with you, nobody is jamming on a large/noticeable scale in New Zealand.