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Text|Big core has material
Editor|Big core has material
In February 2002, Russia and Ukraine were at war and artillery was constantly under fire, and all countries in the world were very concerned about the trend of the situation.
Many countries have used satellite technology to photograph the situation in the Ukrainian war zone, and China and the United States have also released these photos, but the photos captured by the satellites of the two countries have caused heated discussion.
It was noted that the photos captured by American satellites were in color and brightly colored; And the photos taken in China are black and white, somewhat blurry.
So some people questioned, they think that such a comparison judgment, China's satellite technology is obviously lagging behind the United States, is this really the case? What is the difference between a Chinese satellite and a US satellite? Is it true that our satellite technology is inferior to the United States, and the technology is inferior to people?
Satellites used by the United States
From the photos published in the United States, we can tell that this was taken by optical satellites.
Because it can be clearly seen from the picture that not only the situation of the army in the war zone is clear, but even the plants on both sides of the road are very clear, and the whole photo is in high-definition quality, which can be clearly seen that this is captured by optical satellites.
In fact, most of the photos released by the United States are from a company whose main business is to provide satellite monitoring data intelligence, and there will also be a business of leasing satellites.
Some people may not know much about optical satellites, but optical satellites can take pictures so clearly because their imaging principles are the same as those of cameras.
In layman's terms, optical satellites are like eyes, and the way to obtain images is to shine light on the surface of the earth, contact objects and then reflect back, and at the same time, this is why the photos captured by optical satellites can be so high-definition.
So do we have optical satellites? The answer is yes. The mainland has a commercial company of remote sensing satellites before, and the high-resolution remote sensing satellites developed are of excellent quality, and the pieces are colored and very clear.
Not only still lifes are clear, but even high-speed fighter jets can achieve clear capture.
Therefore, our commercial optical satellites are not much different from those of the United States, and our optical satellite technology is equally sophisticated.
Disadvantages of optical satellites
Optical satellites are again colored, and they are clearly shot, and the optical satellite technology of the mainland is not bad, why don't we use optical satellites to shoot the Russian-Ukrainian war zone?
Because optical satellites have limitations, that is, they can only be taken during the day when there is light, and at night or when the weather is bad and the clouds are overcast, they can hardly work, and the photos taken cannot be seen.
In this way, the shortcomings of optical satellites are somewhat fatal, the situation on the battlefield is changing rapidly, and if optical satellites are used, it is impossible to shoot at night, cloudy days and thick clouds cannot be filmed, and it is simply impossible to ensure that the information ahead is grasped around the clock.
The mainland takes into account this shortcoming of optical satellites, so we use another satellite when photographing the Russian-Ukrainian war zone.
Satellites for continentals
The satellite used by the mainland to take photos is "Haise-1", which is our country's first commercial SAR remote sensing satellite, which is characterized by its small size and light compared to other satellites, and the shooting principle of this satellite is active remote sensing imaging.
The optical satellites introduced earlier rely on the reflection of light, and "Haise-1" relies on actively sending electromagnetic wave pulses many times.
For example, a person who cannot see will suddenly retract his hand when he touches something, and this feeling will also reach the brain, and the electromagnetic wave pulse will also eject and feed back to the monitoring station the moment it comes into contact with an object on the earth's surface.
The monitoring station will know what the electromagnetic wave pulses feed back, and after receiving this feedback, it will process and image.
Some people will ask, are the photos taken by such satellites black and white? Yes, because the "Haise-1" imaging does not rely on light, but on electromagnetic waves, so the photo is black and white, without color.
Optical satellites have their fatal drawbacks, they cannot work at night and when there is smoke and clouds, but electromagnetic pulses are completely free of such problems.
The electromagnetic wave pulse will not be affected by these factors, and can maintain the integrity, continuity and comprehensiveness of the observation.
Therefore, when optical satellites are still limited by the influence of bad weather and artillery fire in the war zone, the advantages of SAR remote sensing satellites are reflected.
Why are our satellite photos so blurry?
In the satellite photos taken of Ukraine, there is a clear difference between the photos of China and the United States, the photos of the United States are clear and bright, and even the conditions on the ground can be seen, while the photos provided by China are very blurry and can only be seen in an approximate way.
So, is the image so blurry because our satellites don't have enough resolution? It turns out that it is clearly not!
"Haise-1" is the first 1 m spatial resolution, C-band commercial SAR remote sensing satellite launched in China, looking at the whole world, Haise-1 technology is also far ahead.
SAR remote sensing satellites are different from optical satellites in that they do not take photos directly, and the information collected by the satellites will be sent to the land through electromagnetic waves, and then processed by the processor on the land to form photos.
The amount of data transmitted by remote sensing satellites is very large, and it takes complex data processing to present the image, and the resulting photograph is also very large.
Although the news media can obtain these photos through channels, they do not have the ability to process them professionally, and the release of these photos is very time-sensitive, and in order to rush the media, they also have to adopt cropping and reducing the resolution of the photos.
So the "blurry" photos we see are not professionally processed, so they look like old photos from the last century.
Moreover, the photos released by the media were not for professional rescue, nor did they want to provide detailed maps to anyone, but simply to explain the situation in the Ukrainian battlefield at that time.
It can be seen that blurry photos do not mean that our satellite technology is backward, but simply has not been professionally processed, and the development effect is greatly reduced.
Can Chinese technology match the United States?
China invests a lot in satellite research and development every year, and our country attaches great importance to the research and development of satellite technology.
Can China shoot colorful and high-definition satellites like the United States? Of course there is.
Take the mainland's "Jilin No. 1", which can not only take color satellite pictures with a resolution of up to 0.72 meters, but even has a very powerful function, that is, it can dynamically capture, identify and track targets.
Moreover, if there are too thick clouds in the sky, it will easily affect the shooting effect of the satellite, but for Jilin-1, these are all minor problems and are easily not affected.
The U.S. F-22 fighter is notoriously difficult to track, and it can claim to be absolutely invisible in the air and difficult to capture by satellites. Jilin 1 was able to track not only its flight path, but even its speed.
When Japan first proposed to discharge sewage from the Fukushima nuclear power plant into the sea, which aroused opposition from people around the world, Jilin No. 1 took remote sensing of the Fukushima nuclear wastewater storage site, and the photos were bright and clear.
It can be seen that China's satellite technology has long been different from what it was decades ago, and now China has advanced technology, so there is no need to be presumptuous.
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