Nimbus-6 Satellite Microwave Brightness Temperature Images

1975 to 1976 daily brightness temperature images from the Nimbus-6 Electrically Scanning Microwave Radiometer (ESMR), saved as TIFF files. The dataset contains images from 70-mm photofacsimile film strips, with about 5-10 months of data archived per ZIP file. It was produced by the GES DISC and is based on an instrument that operated until September 15, 1976.

Use Cases

• Analyze brightness temperature patterns from the 0.81 cm (37.0 GHz) horizontal and vertical polarization channels to study cloud liquid water content over oceans.
• Compare ascending and descending orbit swath strips within each image frame to observe diurnal differences in sea ice and open sea signatures.
• Use the geographic grid overlay on each image frame to geolocate and map global microwave emission data from the mid-1970s.
• Investigate the impact of the horizontal channel failure after September 15, 1976, on data continuity for time-series analysis of polar regions.
• Extract brightness temperature values from the 10 (full scale) or 5 (partial scale) parallel imagery strips to study different dynamic ranges for surface composition inference.

Strengths

• Provides global mapping of microwave radiation at 0.81 cm (37.0 GHz) from 1975 to 1976.
• Images contain dual polarization components (horizontal and vertical) until the horizontal channel failure.
• Spatial resolution is approximately 20 x 45 km near nadir for detailed regional analysis.

Limitations

• The horizontal polarization channel failed on September 15, 1976, creating a data gap for that component.
• Data is derived from digitized 70-mm film strips, which may introduce artifacts compared to direct digital recording.
• Temporal coverage is limited to the operational lifetime of the Nimbus-6 ESMR instrument, approximately two years.

Provenance

Source

GES DISC, originally from the Nimbus-6 ESMR instrument.

Collection Method

Data collected by the Electrically Scanning Microwave Radiometer (ESMR) and recorded on 70-mm photofacsimile film strips, later digitized into TIFF files.

Time Range

1975 to 1976, with instrument failure on September 15, 1976.

Freshness

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Geography

Global coverage.