FY2 Product Format Introduction
Transcript of FY2 Product Format Introduction
FY2 PRODUCT FORMAT INTRODUCTION
1 FY2C Normalized Geostationary Projection Dataset File Format
The FY2C Normalized Geostationary Projection Dataset is stored in HDF5 data
format in Normalized Geostationary Projection.
1.1 Introduction of Normalized Geostationary Projection
The normalized geostationary projection describes the view from a virtual
satellite of an idealized earth. Herein, the virtual satellite is in a geostationary orbit,
perfectly located in the equator plane exactly at subsatellite longitude. The distance
between spacecraft and centre of earth is 42164 km. The idealized earth is a perfect
ellipsoid with an equator radius of 6378.137 km and flattening of 1/298.257223563.
The subsatellite longitude of FY2C Normalized Geostationary Projection is
104.5°E.
1.2 About HDF5 file format
HDF5 is a completely new Hierarchical Data Format product consisting of a data
format specification and a supporting library implementation. HDF5 is designed to
address some of the limitations of the older HDF product and to address current and
anticipated requirements of modern systems and applications.
HDF5 files are organized in a hierarchical structure, with two primary structures:
groups and datasets.
HDF5 group: a grouping structure containing instances of zero or more groups or
datasets, together with supporting metadata.
HDF5 dataset: a multidimensional array of data elements, together with
supporting metadata.
Details on HDF5 are at http://www.hdfgroup.org/.
1.3 FY2C dataset struct in HDF5
1.3.1 File information struct
The file information dataset name of HDF5 datase is “/NomFileInfo”.
struct structNOMFileInfo{
char strSatellite[12]; // satellite name : “FY-2C”, “FY-2D” etc.
char strProductID[3]; // product ID: “NOM”
char strProductName[64]; // procut name: “Nomalized Projection Full Disc Image”
float fNOMCenterLat; // idealized subsatellite lantitude: 0.0
float fNOMCenterLon; // idealized subsatellite longitude: 104.5(FY2C)
float fNOMSatHeight; // idealized satellite height: 35785.863km
char strNOMType[12]; // processing mode: “draft” or “fit”
unsigned short iCalTabCreateYear; // year of calibration time (UTC)
unsigned short iCalTabCreateMonth; // month
unsigned short iCalTabCreateDay; // day
unsigned short iCalTabCreateHour; // hour
unsigned short iCalTabCreateMinute; // minute
unsigned short iCalTabCreateSecond; // second
unsigned short iStartYear; // year of time of the first valid scan line (UTC)
unsigned short iStartMonth; // month
unsigned short iStartDay; // day
unsigned short iStartHour; // hour
unsigned short iStartMinute; // minute
unsigned short iStartSecond; // second
unsigned short iEndYear; // year of time of the last valid scan line (UTC)
unsigned short iEndMonth; // month
unsigned short iEndDay; // day
unsigned short iEndHour; // hour
unsigned short iEndMinute; // minute
unsigned short iEndSecond; // second
unsigned short iProcessYear; // year of processing time (UTC)
unsigned short iProcessMonth; // month
unsigned short iProcessDay; // day
unsigned short iProcessHour; // hour
unsigned short iProcessMinute; // minute
unsigned short iProcessSecond; // second
double dEA; // equator radius: 6378137.0 (m)
double dSamplingAngle; // sample angle: 0.00014 (rad)
double dSteppingAngle; // step angle: 0.00014 (rad)
double dObRecFlat; // the reciprocal of earth flattening: 298.257223563
char strComment[128]; // comment
}NOMFileInfo;
1.3.2 Other dataset
The dataset of channel data and angle data has a nadir resolution of 5 km in each
direction.
content dataset name
Calibration table of IR1(1024 float) /CALIR1
Calibration table of IR2(1024 float) /CALIR2
Calibration table of IR3(1024 float) /CALIR3
Calibration table of IR4(1024 float) /CALIR4
Calibration table of VIS(64 float) /CALVIS
IR1 channel data (2288x2288 uint16) /NOMChannelIR1
IR2 channel data (2288x2288 uint16) /NOMChannelIR2
IR3 channel data (2288x2288 uint16) /NOMChannelIR3
R4 channel data (2288x2288 uint16) /NOMChannelIR4
VIS channel data (2288x2288 uint8) /NOMChannelVIS
Satellite zenith distance (2288x2288 float) /NOMSatelliteZenith
Sun zenith distance (2288x2288 float) /NOMSunZenith
Sun/satellite azimuth angle (2288x2288 float) /NOMAzimuth
Sun glint angle (2288x2288 float) /NOMSunGlintAngle
Cloud classification result (2288x2288 uint8) /NOMCloudClassification
The defininition of cloud classification result is in the product of Cloud
Classification.
2 Precipitation Estimation Product
2.1 Format
The files are binary, file head and data are included.
The length of the file head is 1001×2×2 characters, consisting of the record of the
first and the second file head, and the idle segment. Table 1 and Table 2 describe the
record format of the first and the second file head individually.
The length of the data is 1001 columns×501 lines×2byte. The value recorded is
rain rate(mm)×10.
Table 1. Record of the first file head
number byte Byte type description
1 1~12 12 A*12 File name
2 13~14 2 I*2 Byte order of integer
3 15~16 2 I*2 The length of the first file head
4 17~18 2 I*2 The length of the second file head
5 19~20 2 I*2 The length of the filled data
6 21~22 2 I*2 The length of the record
7 23~24 2 I*2 Record number of file head
8 25~26 2 I*2 Record number of data
9 27~28 2 I*2 Type of product
10 29~30 2 I*2 Compress method
11 31~38 8 A*2 Strings of format description
12 39~40 2 I*2 Quality flag of the data
Table 2. Record of the second file head
number byte Byte type description
1 41~48 8 A*8 Satellite name
2 49~50 2 I*2 Element of grid field
3 51~52 2 I*2 Bytes of grid data
4 53~54 2 I*2 Standard value of grid data
5 55~56 2 I*2 Scaling factor of grid data
6 57~58 2 I*2 Code of time limit
7 59~60 2 I*2 Starting year
8 61~62 2 I*2 Starting month
9 63~64 2 I*2 Starting day
10 65~66 2 I*2 Starting hour
11 67~68 8 I*2 Starting minute
12 69~70 2 I*2 Ending year
13 71~72 2 I*2 Ending month
14 73~74 2 I*2 Ending day
15 75~76 2 I*2 Ending hour
16 77~78 2 I*2 Ending minute
17 79~80 2 I*2 Latitude of the top left grid corner
18 81~82 2 I*2 Longitude of the top left grid corner
19 83~84 2 I*2 Latitude of the bottom right grid corner
20 85~86 2 I*2 Longitude of the bottom right grid corner
21 87~88 2 I*2 unit of grid resolution
22 89~90 2 I*2 Horizontal grid resolution
23 91~92 2 I*2 vertical grid resolution
24 93~94 2 I*2 Number of Horizontal grid
25 95~96 2 I*2 Number of vertical grid
26 97~98 2 I*2 Land mask
27 99~100 2 I*2 Value of land mask
28 101~102 2 I*2 Cloud mask
29 103~104 2 I*2 Value of cloud mask
30 105~106 2 I*2 Water mask
31 107~108 2 I*2 Value of water mask
32 109~110 2 I*2 Ice mask
33 111~112 2 I*2 Value of ice mask
34 113~114 2 I*2 Quality flag
35 115~116 2 I*2 Maximum of quality flag
36 117~118 2 I*2 Minimum of quality flag
37 119~4004 482 I*2 spare
2.2 Reference C routines
//open file
if( (fp=fopen(filename,”rb”))==NULL) return; //read the file head:
//read the record of the first file head(40 characters)
char filename[12]; fread(filename,1,12,fp); //filename short a[9]; fread(a,2,9,fp);
//parameters char string1[8];fread(string1,1,8,fp); //strings of format description
short b; fread(&b,2,1,fp); //quality flag of the data
// read the record of the second file head(80 characters)
char string2[8];fread(string2,1,8,fp); //name of the satellite
short c[36]; fread(c,2,36,fp); // time, scope etc.
//read idle segment (3884 characters)
char d[3884]; fread(d,1,3884,fp);
//read data (1001 columns×501 lines×2byte)
char data[501][1001];
for(int j=0;j<501;j++) fread(data[j],1,1001,fp);
//real rainrate=data[j][i]/10.
//close file
fclose(fp);
3 FY-2C Temperature of Brightness Blackbody (TBB) Product
3.1 Format
Data is made of two parts, head record and data record. Head record has two
levels and the first has two parts.
The first level head record (Part one + Part two) The second level head record
Data record … …
Data record
3.1.1 Head Record
Table 1 Part one of the first level head record’s structure sequence byte bytes type Content Value example remark
1 1~12 12 A*12 File name TMGMDDHN.AWX
Fixed Value except
GMDDHN
2 13~14 2 I*2 Order of integer
0 Fixed Value
3 15~16 2 I*2 Length of
head record part one
40 Fixed Value
4 17~18 2 I*2 Length of
head record part two
80 Fixed Value
5 19~20 2 I*2 Length of filling data
1081 Fixed Value
6 21~22 2 I*2 Length of a
record 1201 Fixed Value
7 23~24 2 I*2 Number of head record
2 Fixed Value
8 25~26 2 I*2 Number of data record
1201 Fixed Value
9 27~28 2 I*2 Product type 3 Fixed Value
10 29~30 2 I*2 Zip model 0 Fixed Value
11 31~38 8 A *8
Character String
Illumination of Format
SAT2004 Fixed Value
12 39~40 2 I*2 Quality Mark for Product
2 Fixed Value
Table 2 Part two of the first level head record’s structure
sequence byte bytes type Content Value
example remark
1 41~48 8 A*8 Satellite Name FY2C Fixed Value
2 49~50 2 I*2 Factor of Grid Field 19 Fixed Value
3 51~52 2 I*2 Byte of Grid Data 1 Fixed Value
4 53~54 2 I*2 Reference Mark for
Grid Data 100 Fixed Value
5 55~56 2 I*2 Scale for Grid Data 1 Fixed Value
6 57~58 2 I*2 Code of time frame 1 Fixed Value
7 59~60 2 I*2 Start for Satellite observation: year
2006 Varying Value
8 61~62 2 I*2 month 8 Varying Value
9 63~64 2 I*2 day 15 Varying Value
10 65~66 2 I*2 hour 8 Varying Value
11 67~68 2 I*2 minute 0 Varying Value
12 69~70 2 I*2 End for Satellite observation: year
2006 Varying Value
13 71~72 2 I*2 month 8 Varying Value
14 73~74 2 I*2 day 15 Varying Value
15 75~76 2 I*2 hour 8 Varying Value
16 77~78 2 I*2 minute 25 Varying Value
17 79~80 2 I*2 Upper Left Latitude 6000 Fixed Value 18 81~82 2 I*2 Upper Left 4500 Fixed Value
Longitude
19 83~84 2 I*2 Lower Right
Latitude -6000 Fixed Value
20 85~86 2 I*2 Lower Right Longitude
16500 Fixed Value
21 87~88 2 I*2 Unit of Grid 0 Fixed Value
22 89~90 2 I*2 Space of Lateral
Grid 10 Fixed Value
23 91~92 2 I*2 Space of longitudinal
Grid 10 Fixed Value
24 93~94 2 I*2 Number of Lateral
Grid 1201 Fixed Value
25 95~96 2 I*2 Number of
longitudinal Grid 1201 Fixed Value
26 97~98 2 I*2 If Land Mask exists 0 Fixed Value 27 99~100 2 I*2 Value of Land Mask 0 Fixed Value 28 101~102 2 I*2 If Cloud Mask exists 0 Fixed Value 29 103~104 2 I*2 Value of Cloud Mask 0 Fixed Value
30 105~106 2 I*2 If Water Body Mask
exists 0 Fixed Value
31 107~108 2 I*2 Value of Water Body
Mask 0 Fixed Value
32 109~110 2 I*2 If Ice Mask exists 0 Fixed Value 33 111~112 2 I*2 Value of Ice Mask 0 Fixed Value
34 113~114 2 I*2 If Quality Control is
done 3 Fixed Value
35 115~116 2 I*2 Upper limit of
Quality Control 330 Fixed Value
36 117~118 2 I*2 Lower of Quality
Control 170 Fixed Value
37 119~120 2 I*2 Standby 0 Temporal
Value
38 121~362 242 I*2 Fill Flags 0 Temporal
Value
Table 3 the second level head record’s structure sequence byte bytes type Content Value example remark
FY2C_TBB_I Fixed Value
1 1~64 64 A*64 File Identification By
SAT2004 R1_OTG_200
except observation time
60815_0800. (20060815_0800
AWX )
2 65~72 8 A*8 Format Version AWX2.0 Temporal Value
3 73~80 8 A*8 Producer NSMC CMA Fixed Value
4 81~88 8 A*8 Satellite Flat FY2C Fixed Value
5 89~96 8 A*8 Instrument VISSR Fixed Value
6 97~104 8 A*8 Procedural Version V1.0 Temporal Value
7 105~112 8 A*8 Reserved Temporal Value
8 113~120 8 A*8 Copyright NSMC Fixed Value
9 121~128 8 A*8 Length of extended
filling data 1073 Fixed Value
10 129~120
1 1073 Fill flags 0 Temporal Value
3.1.2 Data Record
Data is saved as two dimensions. The dimension size is 1201*1201. It means that
data has 1201 records, and every record contains 1201 pixels. The first point locates at
the left-up corner, 60ºN & 45ºE. The last pixel locates at the right- down corner, 60ºN
& 165ºE. The data is written from left to right, then from up to down. Each pixel is
one byte.
4 FY2C Total Cloud Amount Product
4.1 Format
Data is made of two parts: head record and data record. Head record has two
records.
The first level head record
The second level head record
Data record
…
…
Data record
4.1.1 The first level head record
Table 1 the first level head record’s structure
Series
Number
Series
number of
byte
Byte
number
type description content
1 1-12 12 Char×12 Sat96 文件名 TCZS0300.AWX
2 13-14 2 Int16 Series number of
integer data
0
3 15-16 2 Int16 Record length of the
first record
40
4 17-18 2 Int16 Record length of the
first record
80
5 19-20 2 Int16 填充段数据长度 881
6 21-22 2 Int16 Record length 1001
7 23-24 2 Int16 Head record number 2
8 25-26 2 Int16 Data record number 1001
9 27-28 2 Int16 Data ID 3
10 29-30 2 Int16 Compress ID 0
11 31-38 8 Char×8 Format describe SAT2004
12 39-40 2 Int16 Quality ID 0
4.1.2 The second level of head record
Table 2 the second level head record’s structure
Series
number
Series number
of byte
Byte
number
Data
type
Description Content
1 41—48 8 Char×8 Satellite name FY2C
2 49—50 2 Int16 Element ID 20
3 51—52 2 Int16 Byte number 1
4 53—54 2 Int16 Basic value 0
5 55—56 2 Int16 Scale factor 100
6 57—58 2 Int16 Time scope ID 0
7 59—60 2 Int16 Start time -year
8 61—62 2 Int16 Start time-month
9 63—64 2 Int16 Start time-day
10 65—66 2 Int16 Start time-hour
11 67—68 2 Int16 Start time-minute
12 69—70 2 Int16 End time-year
13 71—72 2 Int16 End time- month
14 73—74 2 Int16 End time-day
15 75—76 2 Int16 End time-hour
16 77—78 2 Int16 End time- minute
17 79—80 2 Int16 Latitude at the left-up
corner
50
18 81—82 2 Int16 Longitude at the left-up
corner
55
19 83—84 2 Int16 Latitude at the
right-down corner
-50
20 85—86 2 Int16 Longitude at the
right-down corner
155
21 87—88 2 Int16 Grid unit 0
22 89—90 2 Int16 landscape grid 10
23 91—92 2 Int16 Portrait grid 10
24 93—94 2 Int16 landscape grid number 1001
25 95—96 2 Int16 Portrait grid number 1001
26 97—98 2 Int16 Land ID
27 99—100 2 Int16 Land ID value
28 101—102 2 Int16 Cloud ID
29 103—104 2 Int16 Cloud ID value
30 105—106 2 Int16 Water body ID
31 107—108 2 Int16 Water ID value
32 109—110 2 Int16 Ice ID
33 111—112 2 Int16 Ice ID value
34 113—114 2 Int16 Quality ID
35 115—116 2 Int16 The Max. limit of
quality control
1
36 117—118 2 Int16 The Min. limit of
quality control
100
37 119—120 2 Int16 backup
4.1.3 Extended head record
Table3 Extend head record structure
Series
number
Series byte
number
Byte
number
type description content
1 1-64 64 Char×8 File name File name
2 65-72 8 Char×8 Version number AWX2.0
3 73-80 8 Char×8 production NSMC.IBM
4 81-88 8 Char×8 Satellite name FY2C
5 89-96 8 Char×8 Instrument name VISSR
6 97-104 8 Char×8 Processing version V1.0
7 105-112 8 Char×8 reserve
8 113-120 8 Char×8 Version right NSMC
9 121-128 8 Char×8
4.1.4 Data record
Data is saved as two dimensions. The dimension size is 1001*1001. It means data
has 1001 records, every record contains 1001 pixels. The first point locates at the
left-up corner. The last pixel locates at the right- down corner. The data is written
from left to right, then from up to down. Each pixel is one byte.
5 FY2C Total Precipitable Water Product
5.1 Format
Data is made of two parts: head record and data record. Head record has two
records.
The first level head record
The second level head record
Data record
…
…
Data record
5.1.1 The first level head record
Table 1 the first level head record’s structure
Series
Number
Series
number of
byte
Byte
number
type describe content
1 1-12 12 Char×12 Sat96 文件名 TZPS0300.AWX
2 13-14 2 Int16 Series number of
integer data
0
3 15-16 2 Int16 Record length of the
first record
40
4 17-18 2 Int16 Record length of the
first record
80
5 19-20 2 Int16 填充段数据长度 881
6 21-22 2 Int16 Record length 1001
7 23-24 2 Int16 Head record number 2
8 25-26 2 Int16 Data record number 1001
9 27-28 2 Int16 Data ID 3
10 29-30 2 Int16 Compress ID 0
11 31-38 8 Char×8 Format describe SAT2004
12 39-40 2 Int16 Quality ID 0
5.1.2 The second level of head record
Table 2 the second level head record’s structure
Series
number
Series byte
number
Byte
number
type describe content
1 1-64 64 Char×8 File name File name
2 65-72 8 Char×8 Version mumber AWX2.0
3 73-80 8 Char×8 production NSMC.IBM
4 81-88 8 Char×8 Satellite name FY2C
5 89-96 8 Char×8 Instrument name VISSR
6 97-104 8 Char×8 Processing version V1.0
7 105-112 8 Char×8 reserve
8 113-120 8 Char×8 Version right NSMC
9 121-128 8 Char×8
5.1.3 Data record
Data is saved as two dimensions. The dimension size is 1001*1001. It means data
has 1001 records, every record contains 1001 pixels. The first point locates at the
left-up corner. The last pixel locates at the right- down corner. The data is written
from left to right, then from up to down. Each pixel is one byte.
1 2 ---------------------------------Æ1001
2
⏐
⏐
⏐
⏐
⏐.
⏐.
⏐.
⏐
⏐.
↓.
1001--------------------------------Æ1001
6 FY2C Surface Solar Irradiance Product
6.1 Format
Data is made of two parts: head record and data record. Head record has two
records.
The first level head record
The second level head record
Data record
…
…
Data record
The files are binary, file head and data are included.
The length of the file head is 1001×2×2 characters, consisting of the record of
the first and the second file head, and the idle segment. Table 1 and Table 2 describe
the record format of the first and the second file head individually.
The length of the data is 1001 columns×501 lines×2byte. The value recorded is
rain rate (mm)×10.
Table 1. Record of the first file head number byte Byte number type description
1 1~12 12 A*12 File name
2 13~14 2 I*2 Byte order of integer
3 15~16 2 I*2 The length of the first file head
4 17~18 2 I*2 The length of the second file head
5 19~20 2 I*2 The length of the filled data
6 21~22 2 I*2 The length of the record
7 23~24 2 I*2 Record number of file head
8 25~26 2 I*2 Record number of data
9 27~28 2 I*2 Type of product
10 29~30 2 I*2 Compress method
11 31~38 8 A*2 Strings of format description
12 39~40 2 I*2 Quality flag of the data
Table 2. Record of the second file head
number byte Byte number type description
1 41~48 8 A*8 Satellite name
2 49~50 2 I*2 Element of grid field
5
10
15
20
25
3 51~52 2 I*2 Bytes of grid data
4 53~54 2 I*2 Standard value of grid data
55~56 2 I*2 Scaling factor of grid data
6 57~58 2 I*2 Code of time limit
7 59~60 2 I*2 Starting year
8 61~62 2 I*2 Starting month
9 63~64 2 I*2 Starting day
65~66 2 I*2 Starting hour
11 67~68 8 I*2 Starting minute
12 69~70 2 I*2 Ending year
13 71~72 2 I*2 Ending month
14 73~74 2 I*2 Ending day
75~76 2 I*2 Ending hour
16 77~78 2 I*2 Ending minute
17 79~80 2 I*2 Latitude of the top left grid corner
18 81~82 2 I*2 Longitude of the top left grid corner
19 83~84 2 I*2 Latitude of the bottom right grid corner
85~86 2 I*2 Longitude of the bottom right grid corner
21 87~88 2 I*2 unit of grid resolution
22 89~90 2 I*2 Horizontal grid resolution
23 91~92 2 I*2 vertical grid resolution
24 93~94 2 I*2 Number of Horizontal grid
95~96 2 I*2 Number of vertical grid
26 97~98 2 I*2 Land mask
27 99~100 2 I*2 Value of land mask
28 101~102 2 I*2 Cloud mask
29 103~104 2 I*2 Value of cloud mask
30 105~106 2 I*2 Water mask
31 107~108 2 I*2 Value of water mask
32 109~110 2 I*2 Ice mask
33 111~112 2 I*2 Value of ice mask
34 113~114 2 I*2 Quality flag
35 115~116 2 I*2 Maximum of quality flag
36 117~118 2 I*2 Minimum of quality flag
37 119~4004 482 I*2 spare
6.2 Reference C Routines
//open file
if( (fp=fopen(filename,”rb”))==NULL) return;
//read the file head:
//read the record of the first file head(40 characters)
char filename[12]; fread(filename,1,12,fp);
//filename
short a[9]; fread(a,2,9,fp);
//parameters
char string1[8];fread(string1,1,8,fp); //strings of format description
short b; fread(&b,2,1,fp);
//quality flag of the data
// read the record of the second file head(80 characters)
char string2[8];fread(string2,1,8,fp);
//name of the satellite
short c[36]; fread(c,2,36,fp);
// time, scope etc.
//read idle segment (3884 characters)
char d[3884]; fread(d,1,3884,fp);
//read data (1001 columns×501 lines×2byte)
char data[501][1001];
for(int j=0;j<501;j++) fread(data[j],1,1001,fp);
//real rainrate=data[j][i]/10.
//close file
fclose(fp);
7 FY2C Humidity product analysed by cloud information Product
7.1 Format
Data is made of two parts: head record and data record. Head record has two
records.
The first level head record
The second level head record
Data record
…
…
Data record
7.1.1 The first level head record
Table 1 the first level head record’s structure
Series
Number
Series
number of
byte
Byte
number
type description content
1 1-12 12 Char×12 Sat96 文件名 TZCS0300.AWX
2 13-14 2 Int16 Series number of
integer data
0
3 15-16 2 Int16 Record length of the
first record
40
4 17-18 2 Int16 Record length of the
first record
80
5 19-20 2 Int16 填充段数据长度 881
6 21-22 2 Int16 Record length 1001
7 23-24 2 Int16 Head record number 2
8 25-26 2 Int16 Data record number 1001
9 27-28 2 Int16 Data ID 3
10 29-30 2 Int16 Compress ID 0
11 31-38 8 Char×8 Format describe SAT2004
12 39-40 2 Int16 Quality ID 0
7.1.2 The second level of head record
Table 2 the second level head record’s structure
Series
number
Series byte
number
Byte
number
type description content
1 1-64 64 Char×8 File name File name
2 65-72 8 Char×8 Version number AWX2.0
3 73-80 8 Char×8 production NSMC.IBM
4 81-88 8 Char×8 Satellite name FY2C
5 89-96 8 Char×8 Instrument name VISSR
6 97-104 8 Char×8 Processing version V1.0
7 105-112 8 Char×8 reserve
8 113-120 8 Char×8 Version right NSMC
9 121-128 8 Char×8
7.1.3 Data record
Data is saved as two dimensions. The dimension size is 1001*1001. It means data
has 1001 records, every record contains 1001 pixels. The first point locates at the
left-up corner. The last pixel locates at the right- down corner. The data is written
from left to right, then from up to down. Each pixel is one byte.
1 2 ---------------------------------Æ1001
2
⏐
⏐
⏐
⏐
⏐.
⏐.
⏐.
⏐
⏐.
↓.
1001--------------------------------Æ1001
8 FY2C Cloud Classification Product
8.1 Format
Data is made of two parts: head record and data record. Head record has two
records.
The first level head record
The second level head record
Data record
…
…
Data record
8.1.1 The first level head record
NO. Byte
Sequence
Byte
Number
Type description Remarks
1 1-12 12 Char×12 File Name
2 13-14 2 Int16 Byte Order
=0: Intel ≠ 0: Motorola
3 15-16 2 Int16 First File Header Length
4 17-18 2 Int16 Second File Header Length
5 19-20 2 Int16 Fill Field Length(Bytes)
6 21-22 2 Int16 Record Length(Bytes)
7 23-24 2 Int16 Record Number of File Header
8 25-26 2 Int16 Record Number of Data
9 27-28 2 Int16 Product Type
(=3: Grid Product)
10 29-30 2 Int16 Compress Method
(=0: No Compress)
11 31-38 8 Char×8 Format Description
12 39-40 2 Int16 reservation
8.1.2 The second level of head record
NO. Byte
Sequence
Byte
Number
Type Description Remarks
1 41—48 8 Char×8 Satellite Name
5
10
15
20
25
2 49—50 2 Int16 Grid Type
(=21: Cloud Classification)
3 51—52 2 Int16 Byte number
(=1: unsigned char)
4 53—54 2 Int16 No Use
55—56 2 Int16 No Use
6 57—58 2 Int16 Time Scope
(=0: real time)
7 59—60 2 Int16 Year
8 61—62 2 Int16 Month
9 63—64 2 Int16 Day
65—66 2 Int16 Hour
11 67—68 2 Int16 Minute
12 69—70 2 Int16 Reservation
13 71—72 2 Int16 Reservation
14 73—74 2 Int16 Reservation
75—76 2 Int16 Reservation
16 77—78 2 Int16 Reservation
17 79—80 2 Int16 Max Latitude ×100
18 81—82 2 Int16 Min Longitude ×100
19 83—84 2 Int16 Min Latitude ×100
85—86 2 Int16 Max Longitude ×100
21 87—88 2 Int16 Unit
(=0: 0.01 Degree)
22 89—90 2 Int16 Horizontal Grid Size
23 91—92 2 Int16 Vertical Grid Size
24 93—94 2 Int16 Horizontal Grid Number
95—96 2 Int16 Vertical Grid Number
26 97—98 2 Int16 Reservation
27 99—100 2 Int16 Reservation
28 101—102 2 Int16 Reservation
29 103—104 2 Int16 Reservation
30 105—106 2 Int16 Reservation
31 107—108 2 Int16 Reservation
32 109—110 2 Int16 Reservation
33 111—112 2 Int16 Reservation
34 113—114 2 Int16 Reservation
35 115—116 2 Int16 Reservation
36 117—118 2 Int16 Reservation
37 119—120 2 Int16 Reservation
8.1.3 Cloud Type Definition
Value Chinese English
0 晴空海面 Clear Oceans
1 晴空陆地 Clear Lands
11 混合像元 Mixed Pixels
12 高层云或雨层云 Altostratus or nimbostratus
13 卷层云 Cirrostratus
14 密卷云 Cirrus dens
15 积雨云 Cumulonimbus
21 层积云或高积云 Stratocumulus or altocumulus
9 FY2C Snow Fraction Product
9.1 Format
Data is made of two parts, head record and data record. Head record has two levels and the first has two parts.
The first level head record Part one Part two
The second level head record Data record
… …
Data record
9.1.1 Head record
Table 1 Part one of the first level head record’s structure sequence byte bytes type Content Value example remark
1 1~12 12 A*12 File name TSGMYYFR.AWX
Fixed Value except MYY
2 13~14 2 I*2 Order of integer 0 Fixed Value
3 15~16 2 I*2 Length of head record part one
40 Fixed Value
4 17~18 2 I*2 Length of head record part two
80 Fixed Value
5 19~20 2 I*2 Length of filling
data 242
Fixed Value
6 21~22 2 I*2 Length of a
record 362
Fixed Value
7 23~24 2 I*2 Number of head
record 2
Fixed Value
8 25~26 2 I*2 Number of data
record 91
Fixed Value
9 27~28 2 I*2 Product type 3 Fixed Value
10 29~30 2 I*2 Zip model 0 Fixed
Value
11 31~38 8 A *8 Character String Illumination of
Format SAT2004#
Fixed Value
12 39~40 2 I*2 Quality Mark for
Produact Data 0
Fixed Value
Note:Each symbol ‘#’ represent a blank(the same as follows).
Table 2 Part two of the first level head record’s structure
sequence byte bytes type Content Value
example remark
1 41~48 8 A*8 Satellite Name FY2C#### Fixed Value 2 49~50 2 I*2 Factor of Grid Field 7 Fixed Value 3 51~52 2 I*2 Byte of Grid Data 2 Fixed Value
4 53~54 2 I*2 Fiducial Value of
Grid Data 0 Fixed Value
5 55~56 2 I*2 factor of
proportionality for Grid Data
1 Fixed Value
6 57~58 2 I*2 Code of time frame 6 Fixed Value
7 59~60 2 I*2 Oldest time, year YYYY Varying Value
8 61~62 2 I*2 Oldest time, month MM Varying Value
9 63~64 2 I*2 Oldest time, day DD Varying Value
10 65~66 2 I*2 Oldest time, hour 3 Temporal
Value
11 67~68 2 I*2 Oldest time, minute 0 Temporal
Value
12 69~70 2 I*2 Youngest time, year YYYY Varying Value
13 71~72 2 I*2 Youngest time,
month MM
Varying Value
14 73~74 2 I*2 Youngest time, day DD Varying Value
15 75~76 2 I*2 Youngest time, hour 8 Temporal
Value
16 77~78 2 I*2 Youngest time,
minute 0
Temporal Value
17 79~80 2 I*2 Upper Left Latitude 6000 Fixed Value 18 81~82 2 I*2 Upper Left 6000 Fixed Value
Longitude
19 83~84 2 I*2 Lower Right
Latitude 1500 Fixed Value
20 85~86 2 I*2 Lower Right Longitude
15000 Fixed Value
21 87~88 2 I*2 Unit of Grid 0 Fixed Value
22 89~90 2 I*2 Space of Lateral
Grid 50 Fixed Value
23 91~92 2 I*2 Space of longitudinal
Grid 50 Fixed Value
24 93~94 2 I*2 Number of Lateral
Grid 181 Fixed Value
25 95~96 2 I*2 Number of
longitudinal Grid 91 Fixed Value
26 97~98 2 I*2 If Land Mask exists 0 Fixed Value 27 99~100 2 I*2 Value of Land Mask 0 Fixed Value 28 101~102 2 I*2 If Cloud Mask exists 0 Fixed Value 29 103~104 2 I*2 Value of Cloud Mask 0 Fixed Value
30 105~106 2 I*2 If Water Body Mask
exists 1 Fixed Value
31 107~108 2 I*2 Value of Water Body
Mask -1 Fixed Value
32 109~110 2 I*2 If Ice Mask exists 0 Fixed Value 33 111~112 2 I*2 Value of Ice Mask 0 Fixed Value
34 113~114 2 I*2 If Quality Control is
done 3 Fixed Value
35 115~116 2 I*2 upper limit of
Quality Control 100 Fixed Value
36 117~118 2 I*2 Lower of Quality
Control -1 Fixed Value
37 119~120 2 I*2 Standby 0 Temporal
Value
38 121~362 242 I*2 Fill Flags 0 Temporal
Value
Table 3 the second level head record’s structure
sequence byte bytes type Content Value
example remark
1 1~64 64 A*64 File Identification By
SAT2004
FY2C_TSG_ MLT_OTG_ YYYYMMD D_TOAD.A
Fixed Value except
YYYYM
WX##……## MDD (30‘#’ in
total)
2 65~72 8 A*8 Format Version AWX2.0## Temporal
Value
3 73~80 8 A*8 Producer NSMC#CMA Fixed Value
4 81~88 8 A*8 Satellite Flat FY2C#### Fixed Value
5 89~96 8 A*8 Instrument VISSR### Fixed Value
6 97~104 8 A*8 Procedural Version V1.0#### Temporal
Value
7 105~112 8 A*8 Reserved ######## Temporal
Value
8 113~120 8 A*8 Copyright NSMC#### Fixed Value
9 121~128 8 A*8 Length of extended
filling data 234#####
Fixed Value
10 129~362 234 A*234 Fill flags ##……## (234 ‘#’ in
total)
Temporal Value
9.1.2 Data record
Data is saved as two dimensions. The dimension size is 181*91. It means data has
91 records, every record contains 181 pixels. The first point locates at the left-up
corner, 60ºN & 60ºE. The last pixel locates at the right- down corner, 15ºN & 150ºE.
The data is written from left to right, then from up to down. Each pixel is two-byte.
Each grid value ranges from -1 to 100, 0 for water body and 0 to 100 for snow
fraction that is percentage of ratio of snow-cover area to land-cover area.
1 2 ---------------------------------Æ181 2 ⏐
⏐
⏐
⏐
⏐. ⏐. ⏐. ⏐
⏐. ↓. 91----------------------------------Æ181
10 FY2C Outgoing Long wave Radiation Product
10.1 Format
The AWX file of FY-2C OLR is a 1003*1001*2 Byte array. The first record is head record which includes the first-level record and the second-level record. The record length is 2002 Byte. The second record is the head record in character which gives detailed information on the OLR data. The record length is 2002 Byte. From 3rd to 1003rd record there is OLR grid data. Each record has a length of 2002 Byte and every 2 Bytes is an OLR value. The unit of OLR value is W/M**2. The coverage of the grid data is 50N-50S, 55E-155E, and the resolution is 0.1*0.1 latitude/longitude. The size of the grid is 1001*1001. For example, the first row of the grid array (also the 3rd record) stores the 1001 values of OLR at 55.0E, 55.1E, 55.2E……154.9E, 155.0E in the latitude of 50.0N, the second row of the grid array (also the 4th record) stores the 1001 values of OLR at 55.0E, 55.1E, 55.2E……154.9E, 155.0E in the latitude of 49.9N,……from north to south, the 1001st row of the grid array (also the 1003rd record) stores the 1001 values of OLR at 55.0E, 55.1E, 55.2E……154.9E, 155.0E in the latitude of 50.0S.
10.2 A FORTRAN program for reading out the OLR from AWX file
C C THIS PROGRAM READOLR.FOR IS USED TO READ OUT THE FY-2C OLR DATA FROM *.AWX FILES
C 程序 READOLR.FOR 是用于从*.AWX 文件读取 FY-2C OLR 格点场资料
C THE AREA IS:50N-50S,55E-155E,AND THE RESOLUTION IS 0.1*0.1 LATITUDE/LONGITUDE
C 资料地理范围: 50N-50S,55E-155E,数据分辨率: 0.1*0.1 经纬度。
C 2007.9.10 C
LOGICAL*1 N(2002),NN(2002),N1(2002),NNN(2002),L(70),LL(70) CHARACTER*1 AHD(12),HH(10),HHH(8),HEAD(126) INTEGER*2 L1,L2,L3,L4,L5,L6,L7,L8,L9,L10
INTEGER*2 LLL(35) INTEGER*2 YEAR1,MONTH1,DATE1,HOUR1,MIN1 INTEGER*2 YEAR2,MONTH2,DATE2,HOUR2,MIN2 REAL*4 LAT1,LAT2,LONG1,LONG2 INTEGER*2 OUT(1001),OLR(1001,1001),PUT(1001) EQUIVALENCE(NNN(1),AHD(1)) EQUIVALENCE(NNN(13),L1) EQUIVALENCE(NNN(15),L2) EQUIVALENCE(NNN(17),L3) EQUIVALENCE(NNN(19),L4) EQUIVALENCE(NNN(21),L5) EQUIVALENCE(NNN(23),L6) EQUIVALENCE(NNN(25),L7) EQUIVALENCE(NNN(27),L8) EQUIVALENCE(NNN(29),L9) EQUIVALENCE(NNN(31),HH(1)) EQUIVALENCE(NNN(41),HHH(1)) EQUIVALENCE(NNN(49),L(1)) EQUIVALENCE(L(1),LLL(1)) EQUIVALENCE(NNN(1),HEAD(1))
EQUIVALENCE(N1(1),OUT(1)) EQUIVALENCE(NN(1),PUT(1))
C OPEN(1,FILE='FY2C_OLR_MLT_OTG_20070909_2100.AWX',ACCESS='DIRECT',
$ RECL=2002) C OPEN(2,FILE='tt.dat',ACCESS='DIRECT',RECL=2002) C C
C READ THE FIRST HEAD RECORD AND GET THE TIME AND AREA OF OLR DATA
C 读取第 1 条头记录,获取 OLR 资料的时间和地理范围。
C C
READ(1,REC=1) NNN WRITE(6,70) AHD
70 FORMAT(/1X,12A1) C
YEAR1=LLL(6) MONTH1=LLL(7) DATE1=LLL(8) HOUR1=LLL(9) MIN1=LLL(10) YEAR2=LLL(11) MONTH2=LLL(12) DATE2=LLL(13) HOUR2=LLL(14) MIN2=LLL(15) LAT1=LLL(16)/100.0 LONG1=LLL(17)/100.0 LAT2=LLL(18)/100.0 LONG2=LLL(19)/100.0 WRITE(6,81) YEAR1,MONTH1,DATE1,HOUR1,MIN1,YEAR2,MONTH2,DATE2, $ HOUR2,MIN2
81 FORMAT(/1X,'TIME INFORMATION--',5I6,'-',5I6) WRITE(6,82) LAT1,LAT2,LONG1,LONG2
82 FORMAT(/1X,'LATITUDE:',F7.2,'-',F7.2,' LONGITUDE:',F7.2,'-',F7.2) C C READ THE SECOND HEAD RECORD AND GET THE DETAILED INFORMATION ON OLR DATA
C 读取第 2 条头记录
C READ(1,REC=2) NNN WRITE(6,74) HEAD
74 FORMAT(/1X,63A1) C C READ OUT THE OLR GRID DATA
C 读出 OLR 格点场
C DO 1000 I=3,1003
READ(1,REC=I) N1 DO 1001 J=1,1001 OLR(I-2,J)=OUT(J)
1001 CONTINUE 1000 CONTINUE C C
WRITE(6,77) (OLR(1,J),J=1,50) 77 FORMAT(/1X,10I4)
C C
STOP
END