Fy-1c polar orbiting meteorological satellite of china:
Satellite, ground system and preliminary applications
FY-1C Data Receiving and Processing
System
After years of investigation, analysis and
applications of TIROS-N, FY-1A and 1B
data processing system, NSMC set up the
new satellite data receiving and processing
system before the FY-1C satellite was
launched. It is the upgraded of the old
system. This system has three satellite data
receiving stations located in Beijing,
Guangzhou and Urumqi respectively and a
data processing center in NSMC/CMA. The
whole system equipped with new receiving
facilities, communication computers, VSAT
system, HP and SGI work stations and
many kinds of peripherals. It is a large scale
complicated system which can be used to
receive, transmit and process FY-1C satellite
data, and it is also compatible of receiving
and processing the data from NOAA polar-orbiting
meteorological satellites of USA.
This system designed to be operated
automatically for satellite data receiving,
processing, products generating, distributing
and archiving.
Satellite Data Receiving
Polar orbiting meteorological satellite data is
received by three data acquisition stations in
Beijing, Guangzhou and Urumqi. The data
received from both FY-1C and NOAA
satellites in three stations are transmitted to
the data processing center(DPC) in real time.
Three stations are equipped with S-bend
antenna, receiver, communication system
and some special interface such as bit/frame
sychronizer, GDPT and LDPT ingester,
HRPT/GDPT transmission interface,
telemetry interface and so on. HRPT,
GDPT or LDPT data received in Guangzhou
and Urumqi stations are relayed to DPC via
VSAT. The data received in Beiging ground
station are transmitted directly to the DPC
via optical fiber. Figure 1 is the
configuration of three stations.
Figure 1 The configuration of three
stations
Satellite Data Processing
FY-1C and NOAA satellite data is processed
in Data Processing Center in NSMC/CMA.
The Satellite data processing includes data
preprocessing, processing and products
generation. Figure 2 is the over view of the
FY-1C data flow and products processing
system.
The satellite data in this system is processed
into four levels, the level 1A, 1A.5, 1B, 1C
and 1D. Level 1A is the raw data of CHRPT,
GDPT and LDPT. Level 1A.5 and 1B are
preprocessed data sets. 1A.5 is for following
processing in real time. 1B is for data
archive purposes, external user access and
any future required reprocessing. Level 1C is
the inter-mediate data sets for final products
processing. Level 1C include two data sets.
One is the regional data in full resolution
with 15 type of data that include satellite
data of 10 observing bands and solar zenith
angle, satellite zenith angle, azimuth angle
between sun and satellite, the observing time
and NDVI. Another One is the globe data in
4 km resolution with 9 type of data that
include satellite data of 4 selected bands and
solar zenith angle, satellite zenith angle,
azimuth angle between sun and satellite, the
observing time and NDVI. Level 1D is the
final products.
Figure 2 FY-1C data flow and products processing system.
Products from FY-1C and Preliminary
Applications
According to the requests from meteorology,
hydrology, climate changes, agriculture and
environment monitoring, FY-1C system is
designed to produce many kind of products
from 10 bends data. These products can be
classified into four types. There are image,
land, ocean and atmosphere products. Each
type has several products.
Image Products
Images are very important products in FY-1C
processing system. They play a great role
in disaster monitoring, such as forest fire,
flooding, blizzard fatality etc. Image
products of FY-1C include stretched gridded
image, special event images, orbital images,
image mosaics in regional and globe size and
products images. Table 4 is specification on
image products from FY-1C. Figure 3 is an
example of image mosaic from FY-1C in
polar stereographic projection over North
hemisphere.
Figure 3 The image mosaic over North
hemisphere from FY-1C
Table 4 The Specification of Image Products
| Products | Spatial Resolution | Geographic
Coverage | Output Format | Schedule |
| Orbital Images | 1.1km, 2km, 4 km | Pass by pass | gridded image | daily |
| Stretched Gridding | 1.1 km, 2 km, 4 km | Pass by pass | gridded image | daily |
Polar Image
Mosaic | 3.7 km-equator
7.4 km- equator | Over Asia Global | image, archive tape | daily |
| Mercator Image Mosaic | 5.7 km- equator
11.4km- equator | Over Asia Global | imagery | daily |
Special
Event
Imagery | 1.1 km | Selectable
orbit
segments | imagery | daily |
| Products Imagery | Same as Products | Same as Products | imagery | Same as Products |
Land products
Land products are used to monitor the
variation of land cover and environment
changes, such as to use vegetation index to
monitor the crop growing condition over
China or world, to use snow cover data in
research of climate changes. FY-1C system
provides many products over land area in
both regional and global. Table 5 is the
summary of land products. Figure 4 is an
example of vegetation index.
Figure 4 An example of vegetation index in
August 1999
