FY-4A: spectacular transition from liftoff to operation

20-06-2018Source:China Meteorological News Press

Weather prediction is equipped with more refined monitoring data 

Monitoring data provided by FY-4A plays a paramount role in weather prediction and underpins objective and quantitative analysis.

Satellite monitoring data will reflect weather systems and their features and changes on satellite cloud images more accurately. By means of data assimilation technology, satellite monitoring data can be incorporated into numerical weather prediction (NWP) and further elevate prediction accuracy.

Advanced Geosynchronous Radiation Imager (AGRI) onboard FY-4A has refined spatial resolution from 5 kilometers to 2 kilometers. Observation temporal resolution targeted at China and neighboring regions have been shortened from 30 minutes to 5 minutes. When required to meet specific observation demand, data can be transmitted in a shorter time.

Satellite is one of the most seminal methods of marine observation. FY-4A can provide myriad high spatial and temporal resolution observation information for monitoring the trend and intensity transition of typhoon, and weather system evolution in neighboring environmental field.


At 00:11 BJT on December 11,Fengyun-4-01 blasts off the launching pad at Xichang Satellite Launch Center Photo from Xinhuanet 

FY-4A can also provide 500-meter high spatial and temporal resolution images, which reflect refined dynamic information like typhoon cloud structure and its evolution, especially monitoring of typhoon eye area. For instance, prior to the landfall of 13th typhoon in 2017, Hato, data transmitted by FY-4A has provided scientific basis for locking typhoon center and finalizing the intensity.

Severe convective weather monitoring, especially short range nowcasting forecast, has made breakthrough.

Right now, the application team has set up a satellite parameter identification method for short range heavy precipitation, which can realize identification models in different areas of China. Forecasters can also carry out convective system intensity identification, and formulate integrated monitoring products based on data from FY-4A, radar observation, lightning observation, and automatic ground station.

Satellite for climate services

How to elevate operational capabilities of satellites in climate and climate change and tackle bottleneck issues in remote sensing application is one of the most pressing tasks. Combined with climate features in China and national level climate operational demand, Beijing Climate Center (BCC) is pressing ahead with application and achievements transformation of FY-4A satellite materials in climate monitoring, climate models, and climate data services.

Based on FY-4A satellite products, BCC research team has developed experimental monitoring application operational products of key variable factors in Asia monsoon system.

This development is predicated on Asia monsoon monitoring product, bearing significance to enhancing application capabilities of independently developed materials among national level climate operation.

To make satellite products better serve climate operational personnel, BCC has also constructed a exhibition platform of FY-4A product.

Fig. GIIRS scan mode 

High spatial and temporal resolution data has flexed their muscles

Numerical Prediction Center (NPC) of CMA and National Satellite Meteorological Center (NSMC) has assessed and experimented with FY-4A data in GRAPES, with good preliminary results.

Geosynchronous Interferometric Infrared Sounder onboard the satellite can realize vertical probing of temperature and moisture at one hour interval, which has filled up insufficiencies in sparse existing ground stations and limited time frequency.

GIIRS data assimilation model has been set up in GRAPES and is equipped with preliminary direct assimilation capacity.

Lightning Mapping Imager (LMI) can conduct probing of lightning frequency and intensity in China and neighboring regions. When real-time, back-to-back observation data is superimposed on cloud image, monitoring and tracking of severe convective weather will be realized.

FY-4A smart observation model experiment is a new attempt in satellite data assimilation application and realizes the interaction between NWP and observation system.

As the application party, NPC has also proposed concrete requirements in the follow-up design of FY-4A.

At present, FY-4A data has realized preliminary assimilation, and established a series of technical procedures. In the next step, in order to make satellite data put into NWP operational application, a large batch of experiments are needed.

FY-4A can capture sandstorm, fire or blue-green algae

For example, by means of back-to-back observation, the whole forming process of haze can be visible.

Observation data showcase that monitoring capabilities for ecological environment of new generation geostationary satellites represented by FY-4A have been significantly uplifted.

In terms of environmental monitoring, FY-4A has expanded the operation of haze monitoring. Ecological environmental team has conducted product development work of multiple image making and quantifiable monitoring.

FY-4A identification accuracy of sand and dust has been markedly enhanced as well. The newly developed index product has played an active role in sand and dust monitoring.




FY-4A is capable of real-time monitoring for air quality and forest fire.

Especially, in the aspects of surface monitoring, FY-4A can spot fire location very well, with monitoring resolution less than two kilometers. We use its visible channel to detect smoke. Employing the continuous observation, we can calculate the wind speed. Meanwhile, the ecological surface parameters and forest information are also brought into fire point judgment. Based on this advantage, some provincial electric power sector signed agreements with meteorological departments to enhance fire point monitoring.  

Make special weather services more professional

On June 23, 2017, to cope with the rainfall in North China and South China, FY-4A began the 20-hour, every two-minute encryption observation. This was the first time for FY-4A to carry out the emergency weather service. CMA actively promote its application, and put it into use of CCTV News Weather Forecast on June 24.  

Since the beginning of 2017, CMA has developed the FY-4A products and data test application in the field of special and public meteorological services, and plans to establish new satellite products, including technical methods and operational systems towards solar energy resources observation and short-term forecast, highway road temperature monitoring, forest fire risk monitoring and forecasting, aviation meteorological services and lightning monitoring and early warning.

FY-4A application in special meteorological services

There are three main advantages in FY-4A satellite products and data for special meteorological services including high spatial and time resolution, and rich product elements. During the period of trial operation, FY-4A has played important role. On May 15, 2018, North China experienced heat wave weather. The meteorological service research team for FY-4A utilized highway traffic observation data and satellite pixels data to carry out the statistical analysis and establish a revised model. Then, the research team used the model to revise the satellite remote-sensing surface temperature along highway of Beijing-Tianjin and surrounding areas, and then obtained continuously distributed surface temperature on the highway network. It’s more instructive for the traffic management department to response the heat wave. The revise analysis improve the surface temperature volume and show more detailed characters.


The workers are installing FY-4 satellite direct receiving station in Shaanxi on November 21,2017

In addition, the research team also developed series of application such as selecting nine representative power stations to carry out monitoring and short-term forecasting test for photovoltaic arrays using solar energy resources and short-term, integrating FY-4 lightning data into STMAS model to develop radar reflectivity factor algorithm technology.

In future, the research team will continue to improve monitoring and short-term forecasting level of solar energy resources, highway surface temperature, forest grassland fire risk, lightning, etc.

Provide supports for weather modification 

Now, FY-4 satellite weather modification application demonstration project has also been fully launched, which inject new vitality into the weather modification operation.

FY-4 macro-microscopic cloud feature parameters and weather modification clouds classification

Integrating with FY-4 satellite data, real-time L-band radar sounding data and ground observation data, the project team developed the parametric products such as cloud base height, supercooled layer thickness, warm zone thickness and cloud thickness. The team also developed an inversion algorithm for the weather modification microscopic cloud physical parameters such as ice cloud, supercooled water and others.


Images from Fy-4A show that portions of Beijing and northern Hebei are covered by cloud system. 

Based on the FY-4 satellite data and cloud macro-microscopic cloud inversion products, the team developed targeted cloud classification and recognition algorithm. Besides mixed cloud and warm cloud, the technology also can recognize cumulant clouds and hail clouds. The technology is not only recognize cloud top types, but also pay more attention to analyzing the physical processes of cloud precipitation in the vertical direction. At present, the Cloud Precipitation Accurate Analysis System-FY-4 (CPAS-FY-4) has finished the preliminary development. The relevant products have been docked to the CIMISS system and released for the whole country. This system can display many cloud products including precipitation forecast, cloud type, total water vapor, cloud phase, cloud top height and temperature, cloud optical thickness and so on.

Now, these cloud products have been applied to various aspects of the weather modification such as cloud model forecast product verification, operation condition monitoring and analysis, operation design and effect analysis. In the future, the team will continue to establish and improve inversion technology, analysis system, application and products application.


16:30 BJT on May 16,2018, FY-4A geostationary meteorological satellite monitoring image 

FY-4A monitors severe convective weather in Huanghuai Region and Jianghuai Region

Easier to acquire satellite data

CMA developed the FY-4 satellite data service system, which is convenient for users to access satellite products. The users only need to open a folder named FY-4A on the computer, and they can find the data directly and acquire the latest satellite images.

This system is also known as the CIMISS satellite data resource pool. After pre-processing, the huge amount of data from FY-4A observation will be imported into the resource pool with 5 minutes and directly connected to users through the network. From the users’ point of view, there is just one 1.4PB folder containing satellite data in their computer or business system. When they open it, they will obtain cloud images, lightning, surface temperature, sea surface temperature, land aerosols and other various satellite data.

Since FY-4 satellite data resource pool was launched on February 5, 2017, with 79 types of data released. The data volume has reached 370TB, and daily data volume has increased by 760GB. The cumulative visited number of users was 17.98 million and the total amount of accessed data was 161 TB. After the power upgrade, the resource pool has achieved "acceleration" for users.

Due to network bandwidth limitations, except for national-level operational bodies, other domestic and international users cannot realize local virtual storage at present. But, different users could acquire satellite data via direct receiving stations, CMACast, CIMISS ground special network, Internet websites and data-customized modes. CMA is optimizing the technology to provide more convenient channels for users.(Jun.20)


FY-4A, China,True Color Source: National Satellite Meteorological Center 

Reporter: Wan Xia, Huang Bin, Niu Yanyuan, Lai Xuwen, Wang Meijue

Editor: Liu Shuqiao, Hao Jing