>>63879443
This is not how satellites work. You can't park a satellite over a single point on the ground unless that point is on the equator. Anything else will require a constellation. Additionally, one satellite that can observe all of China at once will not have the angular resolution to detect and track individual aircraft. One which can resolve an aircraft will not be able to image all of China in a single pass and so will necessitate a large constellation to maintain constant coverage.