第一个nc文件的信息读取
作者：互联网
1.读入nc文件
from netCDF4 import Dataset
path = "F:\\liulu\\2018satellite_dataset\\NPR_SMOPS_CMAP_D20180101.nc"
dst = Dataset(path, mode='r', format="netCDF4")
2.查看dst
print(dst)
<class 'netCDF4._netCDF4.Dataset'>
root group (NETCDF3_CLASSIC data model, file format NETCDF3):
# 数据来自下列卫星
Satellite: ESA's SMOS, EUMETSAT's MetOp-A and MetOp-B, JAXA's GCOM-W1, NASA's GPM and SMAP
# 数据来自下面元件
Instrument: MIRAS on SMOS, ASCAT on MetOp-A, ASCAT on MetOp-B, AMSR2 on GCOM-W1, GMI on GPM, and SMAP
# 该图像采用可利投影/等距柱状投影
Projection: Plate Carree (Equirectangular Projection)
# 数据覆盖整个地球表面
Latitude_at_Lower_Left_Corner: -90.0
Longitude_at_Lower_Left_Corner: -180.0
Latitude_at_Upper_Right_Corner: 90.0
Longitude_at_Upper_Right_Corner: 180.0
# 产品分辨率为0.25度
Product_Resolution: 0.25 degree
# 数据起始时间为2018/01/01 00:00-23:59
Date_Start: 20180101
Date_End: 20180101
Time_Start: 00:00 UTC
Time_End: 23:59 UTC
# 数据按大端字节序存储，即高字节数据存放在低地址端，低字节数据存放在高地址端
Byte_Order: Big endian
# 产品版本是3.0
Product_Version_Number: 3.0
# 数据无压缩
Data_Compression_Type: No Compression
# Production Location
Production_Location: NOAA/NESDIS/OSPO at Camp Springs, Maryland, USA
# Contact Information和Operation Lead，NOAA是美国国家海洋和大气局
Contact_Information: Science Lead : Xiwu Zhan, NOAA/NESDIS/STAR, xiwu.zhan@noaa.gov
Operation Lead: Limin Zhao, NOAA/NESDIS/OSPO, limin.zhao@noaa.gov
# 数据维度size：经度1440，维度720——正好对应分辨率为0.25
dimensions(sizes): Longitude(1440), Latitude(720)
# 变量（维度）
variables(dimensions): int16 Blended_SM(Latitude,Longitude), int16 NRT_SMOS_SM(Latitude,Longitude), int16 SMOS_SM(Latitude,Longitude), int16 ASCAT_A_SM(Latitude,Longitude), int16 ASCAT_B_SM(Latitude,Longitude), int16 AMSR2_SM(Latitude,Longitude), int16 GMI_SM(Latitude,Longitude), int16 NSMAP_SM(Latitude,Longitude), int16 SMAP_SM(Latitude,Longitude), int16 Blended_SM_SD(Latitude,Longitude), int8 Blended_hour(Latitude,Longitude), int8 Blended_minute(Latitude,Longitude), int8 NRT_SMOS_hour(Latitude,Longitude), int8 NRT_SMOS_minute(Latitude,Longitude), int8 SMOS_hour(Latitude,Longitude), int8 SMOS_minute(Latitude,Longitude), int8 ASCAT_A_hour(Latitude,Longitude), int8 ASCAT_A_minute(Latitude,Longitude), int8 ASCAT_B_hour(Latitude,Longitude), int8 ASCAT_B_minute(Latitude,Longitude), int8 AMSR2_hour(Latitude,Longitude), int8 AMSR2_minute(Latitude,Longitude), int8 GMI_hour(Latitude,Longitude), int8 GMI_minute(Latitude,Longitude), int8 NSMAP_hour(Latitude,Longitude), int8 NSMAP_minute(Latitude,Longitude), int8 SMAP_hour(Latitude,Longitude), int8 SMAP_minute(Latitude,Longitude), int8 Blended_SM_SD_hour(Latitude,Longitude), int8 Blended_SM_SD_minute(Latitude,Longitude), int16 Blended_QA(Latitude,Longitude), int16 NSMOS_QA(Latitude,Longitude), int16 SMOS_QA(Latitude,Longitude), int16 ASCAT_A_QA(Latitude,Longitude), int16 ASCAT_B_QA(Latitude,Longitude), int16 AMSR2_QA(Latitude,Longitude), int16 GMI_QA(Latitude,Longitude), int16 NSMAP_QA(Latitude,Longitude), int16 SMAP_QA(Latitude,Longitude), int16 Blended_SM_SD_QA(Latitude,Longitude)
groups:
3.查看变量variable
# 查看nc文件有哪些变量
print(dst.variables.keys())
# 变量类型为odict_keys
odict_keys(['Blended_SM', 'NRT_SMOS_SM', 'SMOS_SM', 'ASCAT_A_SM', 'ASCAT_B_SM', 'AMSR2_SM', 'GMI_SM', 'NSMAP_SM', 'SMAP_SM', 'Blended_SM_SD', 'Blended_hour', 'Blended_minute', 'NRT_SMOS_hour', 'NRT_SMOS_minute', 'SMOS_hour', 'SMOS_minute', 'ASCAT_A_hour', 'ASCAT_A_minute', 'ASCAT_B_hour', 'ASCAT_B_minute', 'AMSR2_hour', 'AMSR2_minute', 'GMI_hour', 'GMI_minute', 'NSMAP_hour', 'NSMAP_minute', 'SMAP_hour', 'SMAP_minute', 'Blended_SM_SD_hour', 'Blended_SM_SD_minute', 'Blended_QA', 'NSMOS_QA', 'SMOS_QA', 'ASCAT_A_QA', 'ASCAT_B_QA', 'AMSR2_QA', 'GMI_QA', 'NSMAP_QA', 'SMAP_QA', 'Blended_SM_SD_QA'])
4.查看变量属性名称
# 查看nc文件中变量的属性名称
for i in dst.variables.keys():
print('%s: %s' % (i, dst.variables[i].ncattrs()))
# 包括全拼、单位、填充值、变量有效范围、缩放因子、偏移量
Blended_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
NRT_SMOS_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
SMOS_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
ASCAT_A_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
ASCAT_B_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
AMSR2_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
GMI_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
NSMAP_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
SMAP_SM: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
Blended_SM_SD: ['long_name', 'units', 'FillValue', 'valid_range', 'scale_factor', 'add_offset']
# 包括全拼、填充值、变量有效范围
Blended_hour: ['long_name', 'FillValue', 'valid_range']
Blended_minute: ['long_name', 'FillValue', 'valid_range']
NRT_SMOS_hour: ['long_name', 'FillValue', 'valid_range']
NRT_SMOS_minute: ['long_name', 'FillValue', 'valid_range']
SMOS_hour: ['long_name', 'FillValue', 'valid_range']
SMOS_minute: ['long_name', 'FillValue', 'valid_range']
ASCAT_A_hour: ['long_name', 'FillValue', 'valid_range']
ASCAT_A_minute: ['long_name', 'FillValue', 'valid_range']
ASCAT_B_hour: ['long_name', 'FillValue', 'valid_range']
ASCAT_B_minute: ['long_name', 'FillValue', 'valid_range']
AMSR2_hour: ['long_name', 'FillValue', 'valid_range']
AMSR2_minute: ['long_name', 'FillValue', 'valid_range']
GMI_hour: ['long_name', 'FillValue', 'valid_range']
GMI_minute: ['long_name', 'FillValue', 'valid_range']
NSMAP_hour: ['long_name', 'FillValue', 'valid_range']
NSMAP_minute: ['long_name', 'FillValue', 'valid_range']
SMAP_hour: ['long_name', 'FillValue', 'valid_range']
SMAP_minute: ['long_name', 'FillValue', 'valid_range']
Blended_SM_SD_hour: ['long_name', 'FillValue', 'valid_range']
Blended_SM_SD_minute: ['long_name', 'FillValue', 'valid_range']
# 包括全拼、填充值
Blended_QA: ['long_name', 'FillValue']
NSMOS_QA: ['long_name', 'FillValue']
SMOS_QA: ['long_name', 'FillValue']
ASCAT_A_QA: ['long_name', 'FillValue']
ASCAT_B_QA: ['long_name', 'FillValue']
AMSR2_QA: ['long_name', 'FillValue']
GMI_QA: ['long_name', 'FillValue']
NSMAP_QA: ['long_name', 'FillValue']
SMAP_QA: ['long_name', 'FillValue']
Blended_SM_SD_QA: ['long_name', 'FillValue']
注：如果add_offset出现在变量中，则在访问数据的应用程序读取数据后将其添加到数据中。如果scale_factor和add_offset属性同时存在，则在添加偏移量之前先对数据进行缩放。scale_factor和add_offset属性可以一起用于提供简单的数据压缩，将低分辨率的浮点数据作为小整数存储在netCDF文件中。当写入缩放数据时，应用程序应该首先减去偏移量，然后除以缩放因子。
原始数据=存储数据*scale_factor+add_offset
反之，存储数据=(原始数据-add_offset)/scale_factor
5.查看变量属性的具体信息
for i in dst.variables.keys():
print(dst.variables[i])
print('\n')
# dst.variables['Blended_SM']的数据类型为<class 'netCDF4._netCDF4.Variable'>
<class 'netCDF4._netCDF4.Variable'>
# 变量Blended_SM的数据类型为int16，维度为Latitude、Longitude
int16 Blended_SM(Latitude, Longitude)
# Blended_SM的全称为Blended Soil Moisture
long_name: Blended Soil Moisture
# Blended_SM的单位是立方米
units: m^3/m^3
# Blended_SM的填充值为-999
FillValue: -999
# Blended_SM的有效范围是[0,10000]
valid_range: [ 0 10000]
# Blended_SM的收缩因子为1e-04，无偏移量
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 NRT_SMOS_SM(Latitude, Longitude)
long_name: NRT SMOS Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 SMOS_SM(Latitude, Longitude)
long_name: SMOS Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 ASCAT_A_SM(Latitude, Longitude)
long_name: ASCAT_A Soil Moisture
units: Degree of Saturation
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 ASCAT_B_SM(Latitude, Longitude)
long_name: ASCAT_B Soil Moisture
units: Degree of Saturation
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 AMSR2_SM(Latitude, Longitude)
long_name: AMSR2 Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 GMI_SM(Latitude, Longitude)
long_name: GMI Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 NSMAP_SM(Latitude, Longitude)
long_name: NRT SMAP Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 SMAP_SM(Latitude, Longitude)
long_name: SMAP Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 Blended_SM_SD(Latitude, Longitude)
long_name: Standard Deviation of Blended Soil Moisture
units: m^3/m^3
FillValue: -999
valid_range: [ 0 10000]
scale_factor: 1e-04
add_offset: 0.0
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int8 Blended_hour(Latitude, Longitude)
long_name: Hour for Blended Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 Blended_minute(Latitude, Longitude)
long_name: Minute for Blended Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 NRT_SMOS_hour(Latitude, Longitude)
long_name: Hour for NRT SMOS Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 NRT_SMOS_minute(Latitude, Longitude)
long_name: Minute for NRT SMOS Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 SMOS_hour(Latitude, Longitude)
long_name: Hour for SMOS Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 SMOS_minute(Latitude, Longitude)
long_name: Minute for SMOS Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 ASCAT_A_hour(Latitude, Longitude)
long_name: Hour for ASCAT_A Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 ASCAT_A_minute(Latitude, Longitude)
long_name: Minute for ASCAT_A Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 ASCAT_B_hour(Latitude, Longitude)
long_name: Hour for ASCAT_B Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 ASCAT_B_minute(Latitude, Longitude)
long_name: Minute for ASCAT_B Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 AMSR2_hour(Latitude, Longitude)
long_name: Hour for AMSR2 Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 AMSR2_minute(Latitude, Longitude)
long_name: Minute for AMSR2 Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 GMI_hour(Latitude, Longitude)
long_name: Hour for GMI Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 GMI_minute(Latitude, Longitude)
long_name: Minute for GMI Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 NSMAP_hour(Latitude, Longitude)
long_name: Hour for NRT SMAP Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 NSMAP_minute(Latitude, Longitude)
long_name: Minute for NRT SMAP Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 SMAP_hour(Latitude, Longitude)
long_name: Hour for SMAP Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 SMAP_minute(Latitude, Longitude)
long_name: Minute for SMAP Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 Blended_SM_SD_hour(Latitude, Longitude)
long_name: Hour for Spare Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int8 Blended_SM_SD_minute(Latitude, Longitude)
long_name: Minute for Spare Soil Moisture
FillValue: -99
valid_range: [ 0 59]
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -127 ignored
<class 'netCDF4._netCDF4.Variable'>
int16 Blended_QA(Latitude, Longitude)
long_name: QA for Blended Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 NSMOS_QA(Latitude, Longitude)
long_name: QA for NRT SMOS Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 SMOS_QA(Latitude, Longitude)
long_name: QA for SMOS Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 ASCAT_A_QA(Latitude, Longitude)
long_name: QA for ASCAT_A Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 ASCAT_B_QA(Latitude, Longitude)
long_name: QA for ASCAT_B Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 AMSR2_QA(Latitude, Longitude)
long_name: QA for AMSR2 Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 GMI_QA(Latitude, Longitude)
long_name: QA for GMI Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 NSMAP_QA(Latitude, Longitude)
long_name: QA for NRT SMAP Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 SMAP_QA(Latitude, Longitude)
long_name: QA for SMAP Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
<class 'netCDF4._netCDF4.Variable'>
int16 Blended_SM_SD_QA(Latitude, Longitude)
long_name: QA for Spare Soil Moisture
FillValue: -999
unlimited dimensions:
current shape = (720, 1440)
filling on, default _FillValue of -32767 used
6.查看维dimension
print(dst.dimensions.keys())
# 维度数据类型也为odict_keys，只有两个维
odict_keys(['Longitude', 'Latitude'])
7.查看维度size信息
# 获取维度的sizes信息，获得索引范围
for i in dst.dimensions.keys():
print('%s_sizes: %s' % (i, dst.dimensions[i].size))
print('------------------------------------------------------')
# 经度size为1440，纬度size为720，则变量size为1440*720
Longitude_sizes: 1440
Latitude_sizes: 720
标签：文件,FillValue,读取,nc,Longitude,range,long,Latitude,name 来源： https://blog.csdn.net/qq_44955314/article/details/117635678