Brief introduction of FY-4 Satellites


Feng Yun-4 series is China's second generation geostationary meteorological satellites. It is planned to launch in 2016. According to Li Qing, Chief Engineer of scientific experimental satellite, compared with Feng Yun-2, the performance of Feng Yun-4 has been improved in terms of data amount, network transmission bandwidth, product type and quantity and archiving data and applications. It would take over the business of Feng Yun-2 satellite.


The satellite attitude is three-axis stabilized to improve the time resolution of observations and regional mobility. The new generation satellites are designed with an enhanced imagery scanning capability, desirable for monitoring small and medium scale weather systems. It is enabled with vertical atmospheric sounding and microwave detection capabilities to address 3D remote sensing at high altitudes. It is also enabled with solar observations for extreme ultraviolet and X-rays, in a bid to enhance China's space weather watch and warning capability. FY-4 will be made either carrying optical or microwave instruments. An optical satellite will carry onboard a 10-channel 2D scanning imager, an interferometric vertical detector, a lightning imager, CCD camera and an earth radiation budget instrument. The satellite produces earth disc imageries every 15 minutes.


Observing instruments aboard FY-4


·Advanced Geosynchronous Radiation Imager (AGRI). The instrument has 14 channels with a spectral range set between 0.55μm and 13.8μm.

·Geo. Interferometric Infrared Sounder (GIIRS).

·Lightning Mapping Imager (LMI).

·Space Environment Package (SEP).

·Solar X-EUV imaging telescope (SXEUV)

·Data Collection Service(DCS)




CMA Report on Preparation for FY-4


1. Introduction

CMA has long embarked on preparation for Fengyun 4 (FY-4) - its next generation of geostationary meteorological sate llite, a three-axis stabilized platform that shall provide for CMA with enhanced space-based observations in future. Launch of the first flying model is scheduled for 2014 and to serve for the experiment and demonstration of the system. Based on user requirement and technical feasibility, FY-4 mission is outlined as follows.

·To take multiple spectral band measur ements of high temporal resolution and accuracy, to obtain imagery of the earth's surface and cloud, including the segment images; overall increase the capability of CMA in space-based quantitative observation and application.

·To measure the vertical profile of temperature and humidity of the atmosphere with improved detection accuracy and vertical resolution.

· To detect the lightning to obtain t he map that positions the lightning occurrences.

· To broadcast the observational im ages, data and derived products with onboard transmitter.

· To collect the earth environmental measurements from automatic data collection platforms and transmit to users.

· To monitor solar activities and space environment to provide the data for space weather research and service.


2. Payload Characteristics

The instrument should be dev eloped to satisfy user requirement for FY-4 missions in imagery, sounding, lightning ma pping, and space environment monitoring. The following payloads are considered to fulfil the missions.

·Multiple-bands Scan-imaging Radiometer

- Off-axis reflecting optics

- Two independent scanning-mirrors for north-south and east-west directions respectively

- Total 216 sensors for 14 bands from visible to long-wave infrared

- Full-path on-orbit radi ation calibration for all bands


·Atmospheric Interference Sounder

- Off-axis reflecting optics

- Two independent scanning-mirrors for north-south and east-west directions respectively

- 32*4 focal plane arrays for mi d-wave and long-wave infrared bands

- Active and radiate coolers


·Lightning Imager

- Dual-tube for observation to achieve more spatial coverage


·Space Weather Monitor

- To be added


3. Frequencies and Data Transmission

FY-4 use of frequencies shall respect to the need for the increased amount of data in transmission, DCPS, TARS, Tele metry and command. FY-4 provides 1675- 1687MHz HRIT data transmission, 1696--1698MHz LRIT data transmission and WAIB( Weather Alarm Info rmation Broadcast).


Source: National Satellite Meteorological Center

Editor Hao Jing