Vehicle Tethered Balloon Monitoring System Stands Above Expo Park

The Expo site in Shanghai has an area of over 5 square kilometers. Who can take a look at the numerous buildings, mobile crowds and vehicles in the park? Even at any time, the temperature values of different areas can be reported. World Expo's "balloon security" can do it! It rises in the air and uses 6 sharp eyes to view the park scene. It is also a quick hand to convey information, and it can send the sight back to the ground in an instant.

The "vehicle tethered balloon monitoring system" for World Expo, Shanghai, was jointly organized by the Institute of photoelectricity of the Chinese Academy of Sciences and a number of scientific research institutes in China.

Six eyes, three types.

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The development of the large balloon sphere is the thirty-eighth of the CLP Group. The construction of the "eye socket" is the Changchun Institute of Optics and mechanics of the Chinese Academy of Sciences.

These "eye sockets" are not only for "eyes" to block dust and rain, but also to manipulate them to any direction. They can scan extensively in a wide range of views, and can also view the specific targets in detail. The images are highly clear.

{page_break} if there is a fire rising from an obscure corner of Expo Park, in a few seconds, "balloon security" will react to the "infrared eye" which is extremely sensitive to temperature. It will send the image of the anomalous temperature to the ground immediately and give an alarm.

The ground surveillance personnel immediately mobilize another kind of "eye" - HD camera on the balloon. First, use large and wide-angle lens to locate and lock the location of the incident in the large field of view, then push the focal distance along the way until the objects of a few centimeters on the ground are clearly seen.

At the same time, information such as image, temperature and location is sent to the fire department to guide firefighters to eliminate fire.

This "infrared eye" developed by the Shanghai Institute of Technological Physics, Chinese Academy of Sciences, can not only detect fire hazards, but also monitor the ground temperature in the park.

In particular, it can perceive infrared rays in the night and rain fog, and the "balloon security" relies on it in the dark night and bad weather.

"Infrared eye" is also an impartial "judge" of many energy-efficient buildings in the Expo area. The energy consuming building is prone to "fever", and the "judge" who speaks with the data is most fair and credible.

Another kind of "eye" developed by Shanghai Institute of technology -- hyperspectral camera is also a "judge". The content of the evaluation is more: through the spectrum acquired during the day, it can monitor the near atmosphere, the water body of the Huangpu River, the growth condition of vegetation, the material of building surface, and so on. The relevant data will be used as an important basis for evaluation and research.

Overcoming disturbance "line of sight" stability

Such a large balloon floats in the air and moves with the wind. How can we take a steady and clear image and send it back to the ground? Researchers from the Academy of Optics and electronics of the Chinese Academy of sciences have solved this problem.

The big balloon is like a kite, which is led by a long cable and connected to the ground control vehicle equipped with data processing center.

The diameter of the cable is 16 millimeters, compared with the length of a few hundred meters. It is thin and fine. As long as there is a slight wind, the balloon will float, and the summer wind in Shanghai will be uncertain.

In order to ensure that 6 "eyes" can be "observed", researchers installed fiber optic gyro inside and outside their "eye sockets", which is similar to the GPS (Global Positioning System), as the vestibule that helps the human body to maintain balance. It can sense the ballooning of the balloon at any time, adjust the posture and orientation of the eye quickly through the control system and motor, so as to keep the line of sight stable.

Of course, if there are 8 or more gale or thunderstorms or hailstones, "balloon security" must be left in time for shelter.

Heat dissipation will not "heat stroke".

{page_break} the hot summer of Shanghai's dog days is also a difficult problem to test "balloon security".

Meteorological data show that in recent three years, the highest temperature in Shanghai has reached 39.6 degrees Celsius in summer.

The big balloon is in the sky, the sun is shining directly, and the "bake" test is even more significant. A few days ago, the surface temperature of Shanghai was just close to 30 degrees Celsius, and the temperature of the "eye socket" surface had reached 50 degrees Celsius.

In addition, tethered balloon should be "fixed" in the air as far as possible, so that it is not conducive to heat dissipation by means of moving air.

It is well known that the precise photoelectric equipment is especially easy to "heat in the heat".

In order to ensure the normal operation of the 6 eyes, experts from the Institute of Optics and electronics of the Chinese Academy of Sciences use computer simulation to design specially designed heat dissipation windows and cooling passages for the "eye sockets" and arrange the internal structure reasonably, so that "balloon security" is no longer afraid of the heat.

6 "eyes" generate more than 6Gb of data per second, how can they be sent back to the ground quickly? Where does the electrical energy work at high altitude? How can the power supply be kept stable? How to avoid lightning when you encounter a thunderstorm? You may not think that all these problems are solved by the cable with a diameter of only 16 millimeters.

The cable developed by the twenty-third Research Institute of China Electronic Technology Group has implanted a large data capacity optical fiber, power supply line and lightning arrester that can pmit 6 independent wavebands with high quality in a slim body.

According to the project leader, Dr. Zhou Weihu, an optical Research Institute of the Chinese Academy of Sciences,