1. unlike the normal remote-sense Sats on LEO , the GF-4 is in a much higher orbit so it would be much harder to achieve a high resolution ratio..
and it's a
geostationary orbit which means
When a satellite reaches exactly 42,164 kilometers from the center of the Earth (about 36,000 kilometers from Earth’s surface), it enters a sort of “sweet spot” in which its orbit matches Earth’s rotation. Because the satellite orbits at the same speed that the Earth is turning, the satellite seems to stay in place over a single longitude, though it may drift north to south. This special, high Earth orbit is called geosynchronous.
in such a sweet spot, it could '
STARE' at you
all the time if it was set
(GF-4's position over the earth and visual range...LOL)
unlike the LEO Imaging satellites which could only have a
glimpse of the same spot on the earth every a couple of days coz it moves so fast (a couple of hours to complete a orbit)
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2. although we already had quite some
geostationary meteorological satellites
A geostationary orbit is extremely valuable for weather monitoring because satellites in this orbit provide a constant view of the same surface area.
but their resolution ratio is always on the
500m-1km level...
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3. actually India has the same 'PLAN' to put a similar sat in the GEO under the project code '
GEO-HR IMAGER' which is announced to be launched during the 11th 5-year plan(2007-2012), it was supposed to be based on I-1K platform(1.X tons) which is much smaller than GF-4's DFH-4 platform(5.X tons), but the the resolution ratio is also quite impressive - 60 meters...
and France and ESA's projects are more aggressive-- their ratio is around 20 merters..
but all these are either officially cancelled or quite 'quiet' which make the GF-4 is the first or only one of this type so called 'spy ' satellite in the GEO ---------- which is most 'powerful' rightfully...LOL
I suggest you guys to have a research on that Indian similar project to find out what kind of 'satellite' it is , how ISRO defined and describe it and what is the project status at this moment if you are really interested ... LOL...