China News Agency, Shanghai, February 8th: The Winter Olympics blessings from Mars reveal how "Tianwen-1" can complete difficult selfies in space
China News Agency reporter Zheng Yingying
At the Winter Olympics being held in Beijing, players from all over the world are competing vigorously.
In the distant space, "Tianwen-1" has been on Mars for almost a year. While it is diligently exploring Mars, it has not forgotten to bring the already installed elements such as the Winter Olympics emblem, and sent the "Space Edition" to the earth. "Winter Olympics Blessings.
We have "Cosmic Winter Olympics Blessing"
Beijing is the world's first "Double Olympic City" to host the Summer and Winter Olympics, and "Tianwen-1" is China's first interplanetary exploration mission.
In recent years, with the rise of China, "Made in China" spacecraft have gone to space one after another. In addition to "Tianwen-1", the Chinese space station is also in full swing.
Before the "Tianwen-1" went to space, the staff installed the mascots of the Beijing Winter Olympics and Paralympics (Bing Dun Dun, Xue Rongrong) and the emblem on its body.
Previously, Bing Dun Dun and Xue Rong Rong (logos) landed on Mars on the "Tianwen No. 1", and took a photo in the same frame with the Zhurong Mars rover, which was a dream linkage.
Recently, at the opening of the Beijing Winter Olympics, a blessing that traveled 320 million kilometers "falls from the sky" again. .
'Selfie master' takes on space shooting challenge
Although "Tianwen No. 1" has been regarded as a "selfie master" recently, from National Day, New Year, to the New Year of the Tiger, whenever there are major events, it often takes "beautiful photos" and sends them back to the earth to express their thoughts and blessings, but In fact, it is a very challenging thing to "take a good selfie" in space.
According to Wu Di, product director of the 803 Institute of the Eighth Academy of China Aerospace Science and Technology Corporation, the main difficulty in taking pictures on Mars orbit is the uncertainty of the target characteristics of the object being photographed.
When taking pictures, people will choose a suitable angle and shooting mode according to the lighting conditions to achieve the best shooting effect.
While the Tianwen-1 orbiter (referred to as: orbiter) in Mars orbit is in flight, its lighting conditions, exposure range, and the angle after the "selfie stick" is stretched will cause the national flag, the emblem of the Winter Olympics and the body of the orbiter, etc. Optical properties change continuously, and the uncertainty generated by these changes is a great challenge for optical cameras to automatically take pictures.
In addition, due to the use of a lens with a larger field of view, the "mirror" area of the surround device is large, and it may be partially in an extremely bright (sunlighted) state and part in an extremely dark (shaded area) state, while the national flag and the The area of the Winter Olympics emblem is relatively small, and as the orbiter flies rapidly in orbit, the light and dark areas of the orbiter body are also constantly changing.
Considering many shooting conditions, the research and development team of the 803 Institute of the Eighth Academy of China Aerospace Science and Technology Corporation designed an adaptive exposure imaging control strategy centered on the national flag.
"We can independently adjust the exposure time through the calculation of the acquired image conditions, and ensure that a clear image of the national flag can be obtained under the condition of continuous changes in lighting conditions." Wu Di said.
From the video sent back by "Tianwen No. 1" at the opening of the Beijing Winter Olympics, people can also see that the position of the golden surround reflecting sunlight is gradually changing, from the lower right corner to the middle, until the strong The sun shines on the Chinese flag, which is always clearly visible.
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