Koko, what are you going to do over the weekend?
I'm going to play drones~
Ha ~ drone fun?
But it's fun, I also have to use drones to do CT for typhoons
Using "drone" to make "typhoon" "CT" may sound like a bad fit, but this technology has been realized as early as 2020.
Image source: Weather in China
Today, we will tell the story of using drones to detect typhoons.
01
Typhoon and typhoon monitoring
Typhoons are extremely destructive and catastrophic weather systems that can cause serious damage to life and property. China is a country that is frequently affected by typhoons, so it is very important to test typhoons.
In recent years, the relevant technology for typhoon tracking and observation has been continuously developed. In 2002, the Ministry of Science and Technology of the People's Republic of China's social welfare research project "China Landing Typhoon Observation Test" program integrated the automatic weather station observation system and the atmospheric boundary layer observation system, and comprehensively used land-based and mobile observation equipment such as wind profiler, Doppler radar, sounding instrument, ultrasonic anemometer, optical rain gauge, iron tower and mobile observation vehicle.
Image source: sohu.com
In 2018, the China Meteorological Administration launched the marine comprehensive meteorological observation test of high-altitude large-scale unmanned aerial vehicles - the "Haiyan Plan". At the same time, China's meteorological department is also organizing the use of satellites to observe typhoons. For example, in August 2019, the Fengyun-4 A-star Atmospheric Vertical Detector observed Typhoon Lichma, which can complete the target area observation every 30 minutes.
In October 2020, in the observation of Typhoon Langka No. 16, a variety of unmanned aerial vehicles, unmanned airships, airborne lidar, rockets, air balloons, manned aircraft, mobile observation vehicles and satellites were comprehensively used to complete different levels of observation. It can be said that China's typhoon observation platform and technology have been fully developed.
02
How to better observe typhoons?
The figure below is a routine process for typhoon monitoring.
Source: References [1]
If we can monitor a typhoon when it is "born", we can know its "growth trend" and prepare for it in advance. However, typhoons are generated at sea, and there are few observation stations at sea and the distribution is not uniform.
So, we have to get as close to the typhoon as possible and observe it up close. Means of observing typhoons include aircraft, ships, air balloons, radiosondes, satellites, etc. However, these detection methods have their own strengths and shortcomings.
Driving airplanes and ships close to typhoons is estimated to be the first thing most people think of, but let the aircraft ships fight with the wind and waves, which can make the pilot pinch a handful of sweat; the air balloon does not need to be operated, but the air balloon is not easy to control, and it may not be able to float to where we want to be; with the satellite tall, it is ultimately separated by thousands of miles, the dense cloud rain of the typhoon will make the satellite remote sensing signal produce a strong attenuation, that is, the satellite may not be able to see clearly.
So, which typhoon is stronger? Radiosondes came to help.
03
Sonde with CT
What is CT? CT is to use an X-ray beam to scan a certain thickness of the human body to form an image of each level, and finally form a stereoscopic view.
The sonde can play a similar role. A radiosonde, like a flying transmitter, transmits the meteorological data detected and altitude to the ground at any time.
The sonde weighing less than 1 kg is mainly composed of four parts: induction element, conversion device, transmitter and power supply. The sensing element is used to sense the size and change of atmospheric temperature, pressure, and humidity elements; and then converted into a radio signal corresponding to the amount of detection through the conversion device; while the high-frequency radio waves generated by the transmitter of about tens or hundreds of megahertz can be loaded with a detection signal to the ground; the power supply provides the energy source of the entire sounding instrument, which occupies a considerable weight.
Image source: new.qq.com
Above, researchers are preparing to release the ascending sonde carried by the sounding balloon; the following figure shows the downsonde with a parachute.
Don't look at the "down-shot type", it is really very top-notch. The sonde is dropped from the sky above the typhoon, and during the fall of the sonde, the basic meteorological elements such as temperature, air pressure, relative humidity, wind direction and wind speed of the typhoon center will be recorded, just like a CT that has made a hierarchical observation of the typhoon.
So, how to safely and quickly "send" the sonde to the typhoon? At this time, the drone is about to appear.
04
Drone and typhoon monitoring
What kind of drone should be used for typhoon monitoring? The usual home drone is definitely not able to resist, our pterodactyl 10 drone application to fight!
Image source: mp.weixin.qq.com
In order to meet the needs of meteorological detection, the test team has developed a special sounding pod to achieve safe and reliable release of the sonde, and to adapt to the UAV loading load and a large number of safety tests. The modification involves the improvement of the standardized loading and control system of the load, the improvement of multi-load communication and integration technology, the improvement of the aircraft control system and the connection with the meteorological support system. In simple terms, after modification, two detection instrument cabins can be mounted under the wings of the aircraft, and a large number of sounding instruments are installed in the instrument cabin.
Specially made sounding capsule
Once the aircraft arrives at the predetermined position and altitude, the instrument chamber will automatically throw the sonde. During the entire process of the sonde falling from a high altitude to the sea, the sundial instrument continuously measures the longitude and latitude, altitude, temperature, humidity, air pressure, wind speed, wind direction and other data, and cooperates with the millimeter wave radar installed on the aircraft to transmit the data back to the ground information processing center.
Using this data, scientists can perform very realistic three-dimensional imaging of typhoons. In addition, through these data, there will be an opportunity to understand the mechanism of typhoon generation and development, and help to make accurate predictions.
"Sky Pigeon" radar vertical monitoring map
Source: Meteorological Detection Center of China Meteorological Administration
The use of unmanned aerial vehicles for typhoon monitoring is an innovative application after the development of technology, and is a clear embodiment of science and technology serving the national marine power strategy and doing a good job in marine disaster prevention and mitigation. Our pace will not stop, and what we want to build in the future is a comprehensive marine meteorological observation system and a corresponding supporting system that integrates shore-based, sea-based, air-based and space-based.
It is believed that after a comprehensive CT test of the typhoon, even the most ferocious typhoon can be obediently tamed.
bibliography
Liu Deqiang, Feng Jie, Ding Ruiqiang, et al. Review of research progress on typhoon target observation[J]. Advances in Earth Science, 2021, 36(6):15.
[2] What does the success of China's first high-altitude UAV typhoon comprehensive detection test mean?
https://mp.weixin.qq.com/s/L6ZmpG2M_6bzZ9v-NYqx9g
[3] When the typhoon struck, the Pterodactyl 10 UAV fought, and bravely moved forward to boldly ct the typhoon!
https://mp.weixin.qq.com/s/b1sRbxkmP-7c8QdZJ5Elkg
[4] Can drones also detect typhoons?
https://mp.weixin.qq.com/s/GxTVKqMY-gbI70MXoTeQpw
Author: Dr. Weihong Guo, Shanghai Institute of Technical Physics, Chinese Academy of Sciences
EDIT: Tinker Bell
Acknowledgements: Wu Rui, Chief Service Officer of Shanghai Meteorological Bureau; Xu Jianzhong, Shanghai Meteorological Society, provided a scientific review of this paper.
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Source: Shanghai Science and Technology Museum
EDIT: just_iu