Dataset of passive microwave SMMR brightness temperature in China (1978-1987)

This dataset mainly includes the passive microwave brightness temperature obtained from the Scanning Multichannel Microwave Radiometer (SMMR) carried by the Nimbus-7 satellite, including 06H, 06V, 10H, 10V, 18H, 18V, 21H, 21V, 37H, 37V, a total of ten microwave channels with two transits (ascending & descending) brightness temperature per day from October 25, 1978 to August 20, 1987, where H represents horizontal polarization and V represents vertical polarization.

Nimbus-7, launched in October 1978, is a solar-synchronous polar-orbiting satellite. The microwave sensor SMMR is a dual-polarization microwave radiometer that measures the brightness temperature of five frequencies (6.6GHz, 10.69GHz, 18.0GHz, 21.0GHz, 37.0GHz) on the surface. It scans the surface at a fixed incident angle of about 50.3 °, with a width of 780 km, and passes through the equator at noon 12:00 (ascending orbit) and 24:00 (descending orbit). The time resolution of SMMR is daily, but due to the wide distance between swaths, the same surface will be revisited every 5-6 days.

1. File format and naming:

Each set of data is composed of remote sensing data files.

The name and naming rules of each group of data files in the SMMR_Grid_China directory are as follows:

SMMR-MLyyyydddA / D.subset.ccH / V (remote sensing data)

Among them: SMMR stands for SMMR sensor; ML stands for multi-channel low resolution; yyyy stands for year; ddd stands for Julian Day of the year (1-365 / 366); A / D stands for ascending (A) and derailing (D ); subset represents the brightness temperature data in China; cc represents the frequency (6.6GHz, 10.69GHz, 18.0GHz, 21.0GHz, 37.0GHz); H / V represents horizontal polarization (H) and vertical polarization (V).

2. Coordinate system and projection:

The projection method is an equal area secant cylindrical projection, and the double standard parallels are 30 degrees north and south. For more information about EASE-GRID, please refer to

If you need to convert the EASE-Grid projection to Geographic projection, please refer to the ease2geo.prj file, the content is as follows:


projection cylindrical

units meters

parameters 6371228 6371228

1 / * Enter projection type (1, 2, or 3)

0 00 00 / * Longitude of central meridian

30 00 00 / * Latitude of standard parallel



Spheroid KRASovsky

Units dd



3. Data format:

Stored as integer binary, each data occupies 2 bytes. The actual data stored in this dataset is the brightness temperature * 10. After reading the data, you need to divide by 10 to get the real brightness temperature.

Spatial resolution: 25km;

Time resolution: daily, from 1978 to 1987.

4. Spatial range:

Longitude: 60.1 ° -140.0 ° East longitude;

Latitude: 14.9 ° -55.0 ° north latitude.

5. Data reading

Remote sensing image data files for each set of data can be opened in ENVI and ERDAS software.

Data file naming and use method

1. File format and naming:
Each group of data consists of remote sensing data files.
The file names and naming rules of each group of data under SMMR grid China directory are as follows:
Smmr-mlyyydda / d.subset.cch/v (remote sensing data)
Among them, SMMR represents SMMR sensor, ML represents multi-channel low resolution, yyyy represents year, DDD represents Julian day (1-365 / 366), a / D represents ascending orbit (a) and descending orbit (d), subset represents brightness temperature data in China, CC represents frequency (6.6ghz, 10.69ghz, 18.0ghz, 21.0ghz, 37.0ghz), H / V represents horizontal polarization (H) and vertical polarization (V).

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Cite as:

NSIDC. Dataset of passive microwave SMMR brightness temperature in China (1978-1987). National Tibetan Plateau Data Center, 2016. (Download the reference: RIS | Bibtex )

Using this data, the data citation is required to be referenced and the related literatures are suggested to be cited.

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License: This work is licensed under an Attribution 4.0 International (CC BY 4.0)

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Geographic coverage
East: 140.00 West: 60.10
South: 14.90 North: 55.00
  • Temporal resolution: Daily
  • Spatial resolution: 10km - 100km
  • File size: 2,964 MB
  • Browse count: 1,450 Times
  • Apply count: 0 Times
  • Share mode: online
  • Temporal coverage: 1978-10-25 To 1987-08-20
  • Updated time:
Contact Information

Distributor: National Tibetan Plateau Data Center


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