Introduction to the Peoples Republic of China National Satellite Meteorological Center

Introduction

The National Satellite Meteorological Center (SMC) was founded on July 1, 1971. It is a scientific research and operational facility affiliated to the State Meteorological Administration. The main functions of SMC include:

Following the way indicated by the late Premier Zhou Enlai, "We should try our best to develop our own meteorological satellites, and also use data from foreign satellites", SMC started by receiving and utilizing data from foreign satellites, and have coordinated actively with the Ministry of Aerospace to develop Chin's meteorological satellites. On Sept. 7, 1988 and Sept. 3, 1990, two polar orbiting meteorological satellites named FY-1A and FY-B were successfully launched. The ground segment consisted of three receiving stations and a data processing center has fulfilled the tasks of data receiving and processing. The experimental geostationary meteorological satellite (FY-2) is expected to be launched in the time frame of 1996-1998. SMC is now working at the construction of the ground segment for FY-2 meteorological satellite.

SMC has involved in the activities of theoretical and experimental researches on radiation transmission in the atmosphere, the algorithm for meteorological satellite data processing as well as the application of meteorological satellite data. These researches have in turn supported the development of SMC, promoted the meteorological satellite data application in China and also the international exchanges.

By using the ground system, SMC receives and processes meteorological satellite data from both Chinese and foreign satellites. It has played an important role in the fields of weather forecasting, natural disasters monitoring and national economy. Remarkable social and economical benefits have been archived.

Organization of SMC

Under SMC, there are facilities of satellite meteorology research, system design, computer system, operation control and communication, operational and service, system support, etc. The 3 ground stations of Beijing, Guangzhou, Urumqi are also under the supervision of SMC.

FY-1 Polar Orbiting Satellite Program

FY-1 Satellite

The experimental polar orbiting satellite FY-1A and FY-1B were launched respectively in 1988 and 1990. China has decided to continue the FY-1 satellite series and to launch FY-1 C, and D. The preliminary schedule time to launch FY-1 C is in the last half of 90's. Now the satellites are being designed and developed on the basis of FY-1 A and FY-1 B. Besides improving the reliability and extending the life of the satellite the number of channels of scan radiometer will be increased from 5 to 10.

FY-1 B Image (Ocean Color)

The specifications of FY-1 C and FY-1 D are as follows:

Multichannel Visible and IR Scan Radiometer (MVISR) is the major sensor of FY- 1. The total number of channels of the sensor is increased from 5 channels in FY-1 A and B to 10 channels in FY-1 C and D including 4 VIS channels, 3 near IR channels, 1 short wave IR channel and 2 long wave IR channels. The wavelengths are as follows: 
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Channel No.¡@ Wavelength (m)¡@¡@¡@¡@ Primary use
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¡@¡@¡@ 1¡@¡@¡@¡@¡@¡@¡@ 0.58-0.68¡@¡@¡@¡@¡@¡@¡@¡@¡@ Daytime cloud, ice and snow vegetation
¡@¡@¡@ 2¡@¡@¡@¡@¡@¡@¡@ 0.84-0.89¡@¡@¡@¡@¡@¡@¡@¡@¡@ Daytime cloud, vegetation, water
¡@¡@¡@ 3¡@¡@¡@¡@¡@¡@¡@ 3.55-3.93¡@¡@¡@¡@¡@¡@¡@¡@¡@ Heat source, night cloud
¡@¡@¡@ 4¡@¡@¡@¡@¡@¡@¡@ 10.3-11.3¡@¡@¡@¡@¡@¡@¡@¡@¡@ SST, day/night cloud
¡@¡@¡@ 5¡@¡@¡@¡@¡@¡@¡@ 11.5-12.5¡@¡@¡@¡@¡@¡@¡@¡@¡@ SST, day/night cloud
¡@¡@¡@ 6¡@¡@¡@¡@¡@¡@¡@ 1.58-1.64¡@¡@¡@¡@¡@¡@¡@¡@¡@ Soil humidity, ice/snow distinguishing
¡@¡@¡@ 7¡@¡@¡@¡@¡@¡@¡@ 0.43-0.48¡@¡@¡@¡@¡@¡@¡@¡@¡@ Ocean color
¡@¡@¡@ 8¡@¡@¡@¡@¡@¡@¡@ 0.48-0.53¡@¡@¡@¡@¡@¡@¡@¡@¡@ Ocean color
¡@¡@¡@ 9¡@¡@¡@¡@¡@¡@¡@ 0.53-0.58¡@¡@¡@¡@¡@¡@¡@¡@¡@ Ocean color
¡@¡@ 10¡@¡@¡@¡@¡@¡@¡@ 0.90-0.965¡@¡@¡@¡@¡@¡@¡@¡@ Water vapor
The instantaneous field of view of the sensor is 1.2 urad and the resolution at subpoint is 1.1 Km. The scan rate of MVISR is still 6 lines/second and total pixel of every scan line is 20480. The High Resolution Picture Transmission of FY-1 C and D is named CHRPT. It is considered that the system which receives and processes HRPT/NOAA- Now data can receive and process CHRPT with updating as few as possible.

The scan rate of MVISR is 6 lines/second, the words of every channel are 2048 and the total words of 10 channels are 20480. Adding the sync and auxiliary information there are 22180 words every scan lien and 10 bits every word. The bit rate is 1.3308 Mbps, just twice as many as the bit rate of HRPT/NOAA-Now. The modulation of CHRPT data is PSK and bit format is split phase. The transmission frequency of CHRPT has not been decided but the data format will be similar to the HRPT/NOAA-Now data format to be easy to process CHRPT data by HRPT/NOAA-Now data processing system.

FY-2 Meteorological Satellite

FY-2 Satellite

The FY- 2 meteorological satellite will be located in the geostationary orbit at an altitude of 35800 kilometers over 105 degrees E. The satellite is a cylinder of 2.1m by 1.6m. The attitude of the satellite is spin stabilized with a speed of 100I 1 rotation/min. Its main functions are:

The scan radiometer obtains a full view image once an hour. It includes three channels of visible (0.55-1.05um), infrared (10.5-12.5 um) and water vapor (6.2-7.6 um). The sub-point resolution of visible channel is 1.25 Km while infrared channel and water vapour channel are about 5 Km. The reflective radiation of cloud and earth surface on daytime can be obtained by visible channel; the infrared radiation of diurnal cloud and earth surface can be obtained from the infrared channel, and the water vapour content of middle and upper atmosphere can be obtained by the water vapour channel. By using these raw cloud image data, various kinds of image and meteorological parameter can be processed for the users.
To collect and transmit in situ observation data from the DCP for the meteorology, oceanography and hydrology.
To broadcast the stretched digital image, low resolution cloud image, synoptic map and processed products for users.
Space environmental monitoring.
FY-1 Data Receiving and Processing System

¡@ FY-1 Beijing Receiving Station

The meteorological satellite data receiving and processing system consists of three ground stations located in Beijing, Guangzhou, Urumqi respectively and a data processing center in SMC. It was constructed as a key project at national level on the "Seventh Five Year Plan" of China. This system was completed in Dec. 1987. It was formally examined and accepted by the Chinese Government soon after and was immediately put into operation. The system has successfully accomplished the tasks of data receiving, transmitting, processing and product distributing for the FY-1A and FY- 1B satellites. The system also holds responsibility for receiving and processing the data from NOAA satellites.

FY-2 Meteorological Satellite Ground System

The ground system of FY -2 meteorological satellite is a multifunctional and real-time operation system. It is constructed as a key project at national level on the "Eighth Five-Year Plan" of China. The systems includes the Command and Data Acquisition Station (CDAS), the Data Processing Center (DPC) and Satellite Operation Control Center (SOCC), the Turn Around Ranging Stations (the main station is in Beijing, the TARS are in Guangzhou, Urumqi and Australia), a communication system, the Data Collection Platforms (DCP), the Medium-Scale Data Utilization Stations (MDUS), the Small-Scale Data Utilization Stations (SDUS), and Facsimile or cloud image receiving stations S-FAX etc.

The major functions of the system include: managing the spacecraft, receiving and handling the satellite data, and distributing the data processed to the users.

Data Receiving of FY-1 Satellite

The ground stations receive HRPT, APT, DPT and telemetry data at the time when FY-1 and NOAA satellites are passing through. All received data are transmitted to the Data Processing Center in realtime. To enhance the reliability, the DPT, HRPT and telemetry data are input to the ground station computer by a dedicated interface for playback when the telecommunication circuit is suspended.

Command and Data Acquisition of FY-2

FY-2 CDA Station in Beijing

The command and data acquisition station plays a role for information and command exchange between FY-2 satellite and ground system. Its main tasks are: receiving the raw data with a speed of 14Mbps by an antenna of 20m diameter, creating and broadcasting the stretched digital image with a data speed of 0.6 Mbps, relaying the low resolution cloud image and synoptic map, receiving and processing telemetry and space environmental monitoring data, remote controlling to the payloads, receiving data from DCP, exchanging data with data processing center and satellite operational control center, and making up a turn-around ranging system for the satellite locating together with other three stations (Urumqi, Guangzhou and Melbourne in Australian).

Computer System

Computer Room of SMC

The data processing computer system is mainly composed of three parts: FY-1 meteorological satellite data processing system, FY- 2 meteorological satellite data processing system and product distributing service system.

The FY-1 meteorological satellite data processing system consists of 2 IBM S/1 front-end computers, 2 IBM 4381-P03 main processors and some image processors. The memory of 4381-P03 is 16 MB. The software package of the meteorological satellite data processing runs the 4381-P03 on the MVS/SP operational system.

The FY-2 meteorological satellite data processing system is composed of 2 SUN 4/490 front-end computers, 2 FUJITSU M770-10 main processors and a SUN 4/490 image work station. The memory of M770-10 is 64 MB, with a 128MB system storage and a software package for running MSP/EX operational system and programmes for geostationary meteorological satellite data processing and applications.

Products distribution service system is composed of a IBM4381-P03 main computer, 2 IBM S/1 communication processors, a IBM 3725 communication controller and local networks. It is used to broadcast and distribute products to local and remote users.

Front-end computer, image processor and main processor in the data processing system are all linked by high speed channel. Communication between FY-1 and FY-2 systems is through two ways; channel linking and disc sharing. The total disc capacity of the whole system is about 100 GB.

Scientific Research

The scientific research of satellite meteorology is very important for the development of satellite meteorology. As in the other countries, the development of China's satellite meteorology is accompanied with large amount of research work from the beginning, the gained results of these researches have greatly improved the development of the operational work. With the policy of letting scientific research serving the operational work and satellite engineering, the Satellite Meteorological Center applies research results extensively into its operational work and satellite engineering.

Now the labs of solar spectrum, radiative spectrum and simulating atmospheric absorption have been set up in the Satellite Meteorological Center for supporting the operational and engineering tasks with the needed theoretical and technical basis. Besides, it also carries out the theoretical studies of meteorological satellite remote sensing and the data retrieval in order to improve the retrieval accuracy of landsurface parameter and atmospheric parameter; the researches of image processing technique and satellite orbit prediction method for the better satellite image location; the researches of satellite data application in the severe weather analysis and forecast such as typhoon and rainstorm etc; the study of the impact of digital data on numerical weather forecast model. These studies and researches have played an important role in popularizing the application of satellite data in China.

Combined with the researches of global climate change, the Satellite Meteorological Center has a further study on the method of climatic parameter extraction and analysis in recent years.

The Satellite Meteorological Center has taken an active part in making the planning of China's meteorological satellite and the system design of the satellite and the related ground systems.

For helping weather stations and various users to receive and use the meteorological satellite data directly, the Satellite Meteorological Center is engaged in the researches of satellite data receiving and communication techniques and manufacture of both hardware and software for various meteorological satellite data applications systems. Nowadays, the PC based polar orbiting and geostationary meteorological satellite data receiving and processing systems developed by SAC are extensively used over the country, these systems have greatly enhanced the capability of the weather stations in weather monitoring and forecast.

PC Based Polar Orbiting Meteorological Satellite Data Receiving and Processing System

The PC based polar orbiting meteorological satellite data receiving and processing system is developed by the Satellite Meteorological Center. The hardware of the system includes a data ingestor for the HRPT data of FY-1 and NOAA satellites, a personal computer (PC 386), a color image card and a monitor. Other equipments such as tape recorder and video converter etc. are selectable for the system. This PC based system is good at receiving and processing the AVHRR and TOVS data from polar orbiting meteorological satellites.

The system contains many data processing routines that can be used for satellite orbit prediction, HRPT data ingesting and recording, real time satellite cloud image monitoring, satellite data preprocessing, landmark navigation, the playback of preprocessed single channel or multi-channel composite image with various resolutions, setting longitude, latitude and landmark on the image, producing multiple composite image and stretched single orbit image, generating quantitative data etc.. With the above mentioned routines, the system can provide service to forest fire monitoring, vegetation monitoring, sea surface temperature detection, ice snow cover monitoring, river mouth silt sedimentation monitoring, atmospheric temperature and humidity distribution detection, conventional meteorological data processing, display and overlap on satellite data. For the convenience of user, the data processing of the system is handled by menu. Besides, the system also has the functions of system test, data archiving, file management and image demonstration etc..

The PC Based Geostationary Meteorological Satellite S-VISSR Data Receiving and Processing System

The PC based geostationary meteorological satellite S-VISSR data receiving processing, DOS and X-Windows, is recently developed by the Satellite Meteorological Center, it is mainly for receiving and processing the hourly S- VISSR data from FY-2 and GMS satellites. The system can handle not only geostationary satellite images, but also several kinds of weather information such as conventional weather report and grid point data etc. Through the system, conventional meteorological data can be overlapped on satellite image for further analysis. As the system connects with the receiver through the data ingestor, it is able to acquire and process the S-VISSR data in real time. It also has the capability to store all (or partial) pixels of each scan line in full (or sampled) resolution for meeting the various requirements of user. For easy handling, the system accepts a integrated configuration and operates in menu and man-machine interaction modes. In addition, there is an automatic batch job mode in the system.

Satellite Image Covered by Conventional Data

GMS-4 Disk Image (VIS)

For Further Information Contact:

Basishiqiaolu No. 46
Western Suburb
Beijing 100081 P.R. China
Tel: 832 7395
Telex:22094 FDSMA CN
Fax: 8321135
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