数据说明
数据说明
Each AHI band has its own characteristics.
Truecolor images from a combination of the three visible bands (blue: #1, 0.47 µm; green: #2, 0.51 µm; red: #3, 0.64 µm) appear as if seen by the human eye.
Near-infrared (NIR) bands #4–6 (0.86, 1.6, and 2.3 µm) provide cloud physical parameter data such as information on the water/ice phase,
particle size, and optical thickness.
Solar reflectance differences in the visible and NIR bands enable the collection of surface property data such as information on snow/ice cover and vegetation.
The short wave infrared band #7 (3.9 µm), which is inherited from the MTSAT series, is used to monitor low-level cloud, fog, wildfires, and other phenomena.
Three bands from #8–10 (6.2, 6.9, and 7.3 µm) in the water vapor absorption band are available, as opposed to the single band of the MTSAT series.
The water vapor bands are sensitive to middle-to-upper tropospheric humidity, and differences in sensitivity between them provide humidity vertical profile information.
Band #11 (8.6 µm) is used for thin ice cloud monitoring in conjunction with other atmospheric window bands.
Bands #10 and #11 are sensitive to volcanic SO2 gas.
Band #12 (9.6 µm), which is in the ozone absorption band, is used to monitor stratospheric ozone and (indirectly) potential vorticity.
There are three bands (#13–15; 10.4, 11.2, and 12.4 µm) in the 10–12 μm atmospheric window as opposed to the two (known as “split window bands”) of the MTSAT series.
These are used to monitor ice crystals/water, lower water vapor, volcanic ash, sea surface temperature, and other phenomena.
The atmospheric window band is present on most meteorological satellites and is mainly used at operational weather centers to support real-time weather analysis and forecasting.
Band #16 (13.3 µm), which is in the CO2 absorption band, is used for cloud top height assignment and the estimation of thin cirrus opacity.
日本向日葵卫星官方FTP（ftp.ptree.jaxa.jp）提供近两种格式的数据下载：HSD格式和NetCDF格式。根据其数据说明，
1、HSD
该类型数据由日本气象厅（JMA）提供最新30天的数据。向日葵卫星主要载荷是高级“向日葵”成像仪（AHI，Adcanced Himawari Imager），其数据是DN值。
2、NetCDF
该类型数据是，向日葵L1级格点数据（L1 Gridded Data），由"日本宇宙航空研究开发机构"(JAXA)下属的“地球观测研究中心”（Earth Observation Research Center，EORC)从HSD格式数据近实时转换而来。 数据包含了反照率（Albedo，reflectance*cos(SOZ) of band01~band06）和亮温（Brightness temperature of band07~band16）。
数据类型
dtype用于自定义类型。i1，i2，i4，i8表示int8，int16，int32，int64。S20表示特定长度的字符串
HSD数据
读取DAT文件：01 | 02 (对结果进行切割:txt|截图 )
DAT文件包含了12个部分（block）
NetCDF数据
# Available Himawari L1 Gridded Data
## Full-disk
Projection: EQR
Observation area: 60S-60N, 80E-160W
Temporal resolution: 10-minutes
Spatial resolution: 5km (Pixel number: 2401, Line number: 2401)
2km (Pixel number: 6001, Line number: 6001)
Data: albedo(reflectance*cos(SOZ) of band01~band06)
Brightness temperature of band07~band16
satellite zenith angle, satellite azimuth angle,
solar zenith angle, solar azimuth angle, observation hours (UT)
查看nc文件内容（01|）
print(nc_data.keys())
'band', 'band_id', 'end_time', 'geometry', 'geometry_parameters', 'latitude', 'longitude', 'sd_albedo_03', 'start_time',
'tbb_07', 'tbb_08', 'tbb_09', 'tbb_10', 'tbb_11', 'tbb_12', 'tbb_13', 'tbb_14', 'tbb_15', 'tbb_16', 'time']>
# 查看纬度第一个值(最北)60°
data0 = nc_data['latitude'][0:][0]
# 查看经度第一个值（最西）80°
data0 = nc_data['longitude'][0:][0]
