China's Space Program News Thread

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Blitzo

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I just discovered these magazines ("Go Taikonaut") which seem to be quite authoritative accounts and reviews of Chinese space activities :bowdown:
Found by goolging passages posted by escobar on SDF...

Issues 14 and 15 (jan 2015 and april 2015 this year)
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And there's also a website...
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Ultra

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Wow, GF-4 will be perfect to provide C4ISR in westpac and to support naval surveillance (namely to support carrier tracking).

Geosynchronous orbit means they can maintain watch over the westpac permanently without having to wait for other satellites to orbit overhead. I'm sure resolution will be steadily improved over the years and newer rockets will mean heavier satellites lofted into orbit as well


Yeh, but resolution is horrible, 50 meters!
A Nimitz-class aircraft carrier would only be 6 pixels long and 1 pixel wide!
 

Blitzo

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Yeh, but resolution is horrible, 50 meters!
A Nimitz-class aircraft carrier would only be 6 pixels long and 1 pixel wide!

I've been thinking about that, and I agree that resolution can still be improved, however GF-4 even at its present resolution can potentially be useful in carrier tracking. It would rely on other assets to cue a search pattern in a particular region (whether it be ELINT sats or even human intelligence), looking for the distinctive pattern of a carrier and its escorts. If there is real time video or even near real time rapid picture taking, it would also be possible to track the distance that a suspected CSG has moved and potentially determine if its speed may be indicative of a CSG.
The other option is to allocate a satellite to continuously take pictures of a carrier at port (when a carrier is at port there are a variety of high profile articles abound), say at Yokosuka, and to track its progress with multiple pictures per hour to keep up to date on the location of the 6x1 pixel sized object, being confident that the object tracked is a carrier due to having "confirmed" its presence by way of keeping a tag on it since it was confirmed to be at dock.

In other words, it is the continuous passive nature of a geosynchronous satellite which is important, and it can complement an array of other LEO satellites, SAR satellites, ELINT satellites, and other ISR systems. For something as distinctive as a carrier, finding it would be the first hard part, but if you have a geosynchronous satellite that can even keep track of a pattern of pixels to cue and/or be cued by other satellites and assets, then positively IDing a carrier could conceivably be much easier than before.

Another question I've posed on a few other forums is just what kind of resolution the best geosynchronous satellites have at the moment. Most geosynchronous satellites are weather sats, and the best resolution I've seen after a quick search is 500m for the US's next generation GOES-R weather sats.
So I think GF-4's resolution might actually be pretty good compared to present generation geosynchronous satellites.
 

Blitzo

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Gaofen series of satellite is touted as China's first high definition earth observable satellite, the name "Gaofen" means "high definition". Gaofen-1 is a 2 m resolution satellite with a launch mass of 1080 kg. The thing I found it interesting is the fact that Gaofen-1 was launched in April 26, 2013.

Now Dubai, a country that has never launch a satellite before, designed and launched a earth observable satellite called DubaiSat-1 back in July 2009. DubaiSat-1 has a resolution of 2.5 m.

On 21 November 2013, same year China's Gaofen-1 was launched, Dubai launched DubaiSat-2, weighing only 300 kg, it has a highly advanced propulsion system known as The Hall Effect Propulsion System; along with the High Resolution Advanced Imaging System (HiRAIS) which can capture images at 1 m resolution.

It is almost not until almost a year later on September 2014, did China launched Gaofen-2 with a 1 m resolution camera.

So how did China lag so far behind in term of imaging satellite technology? China a supposed upcoming super power to challenge the US, can't even compare to Dubai, a country that has never launch a satellite before nor design one before managed to designed and launched satellites that's more advanced than China and years before China. Let's not even compare to India, a third world country with even smaller budget than China.

India launched Cartosat-1, a 2.5 m resolution rarth observation/remote sensing satellite back in May 2005, a good 8 years before China's Gaofen-1. They then follow up with Cartosat-2 which weighs only 680 kg and carries a camera with resolution of 0.8 m - a good 7 years before China's Gaofen-2. They followed up with Cartosat-2A and 2B, and now they are almost ready to launch Cartosat-3 in 2017, with a resolution of 0.25 m!

I just find it bizzare how China allows itself to lag so far behind in this key area, that even a complete novice to this sector like Dubai is able to outsmart China's best effort.

The dubaisats were "developed" with the Satrec Initiative of South Korea, who are far from novices in satellite development. Basically, the Dubaisats are Korean satellites. It's not like Dubai suddenly developed the technology indigenously.

Also, the Gaofen satellites are not China's first LEO EO satellites. The Yaogan series preceded them by many years... and they are basically military in nature, whose specifications have not been released. During the cold war there were also a series of Fanhui ShiWeixing (recoverable recon satellites) launched, whose resolution we also do not know.

The only reason we know the specs of the Gaofen satellites is because they are part of the CHEOS network which is mostly civilian in nature. I would expect the Yaogan series to have superior resolution to the Gaofen satellites.


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seriously, you could have answered your own curiosities through a few google searches and a few logical deductions.
 

escobar

Brigadier
Tianzhou-1 cargo ship to rendez-vous with TG-2 in 2016...
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escobar

Brigadier
Gaofen series of satellite is touted as China's first high definition earth observable satellite, the name "Gaofen" means "high definition". Gaofen-1 is a 2 m resolution satellite with a launch mass of 1080 kg. The thing I found it interesting is the fact that Gaofen-1 was launched in April 26, 2013.

Now Dubai, a country that has never launch a satellite before, designed and launched a earth observable satellite called DubaiSat-1 back in July 2009. DubaiSat-1 has a resolution of 2.5 m.

On 21 November 2013, same year China's Gaofen-1 was launched, Dubai launched DubaiSat-2, weighing only 300 kg, it has a highly advanced propulsion system known as The Hall Effect Propulsion System; along with the High Resolution Advanced Imaging System (HiRAIS) which can capture images at 1 m resolution.

It is almost not until almost a year later on September 2014, did China launched Gaofen-2 with a 1 m resolution camera.

So how did China lag so far behind in term of imaging satellite technology? China a supposed upcoming super power to challenge the US, can't even compare to Dubai, a country that has never launch a satellite before nor design one before managed to designed and launched satellites that's more advanced than China and years before China. Let's not even compare to India, a third world country with even smaller budget than China.

India launched Cartosat-1, a 2.5 m resolution rarth observation/remote sensing satellite back in May 2005, a good 8 years before China's Gaofen-1. They then follow up with Cartosat-2 which weighs only 680 kg and carries a camera with resolution of 0.8 m - a good 7 years before China's Gaofen-2. They followed up with Cartosat-2A and 2B, and now they are almost ready to launch Cartosat-3 in 2017, with a resolution of 0.25 m!

I just find it bizzare how China allows itself to lag so far behind in this key area, that even a complete novice to this sector like Dubai is able to outsmart China's best effort.


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There is a good post about spatial resolution from member schlieffen:
https://www.sinodefenceforum.com/chinas-space-program-news-thread.t1143/page-283#post-303784
 
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