Explorer-7 Nighttime Terrestrial Radiation Temperature Measurements

Explorer-7 satellite data contains nighttime temperature values measured by a white sensor designed for terrestrial radiation. The dataset covers the mission period from November 15, 1959, to May 24, 1960, and was produced by Principal Investigator Verner E. Suomi of the University of Wisconsin. It represents the first set of Earth-looking radiation data collected from space.

Use Cases

• Analyzing temporal trends in nighttime terrestrial radiation using the temperature values and timestamp data.
• Mapping the geographic distribution of measured radiation by joining temperature readings with the provided geolocation information.
• Correlating satellite orbit parameters, such as perigee and apogee, with variations in the measured radiance and temperature fields.
• Studying instrument performance and data characteristics from early space missions using the original IBM EBCDIC format records.

Strengths

• Contains the first set of Earth-looking thermal radiation data collected from space, providing historical significance.
• Covers a continuous 6-month mission period from November 1959 to May 1960.
• Includes multiple related data fields such as temperature, radiance, geolocation, and orbit information in a single file.

Limitations

• Data is stored in an obsolete IBM EBCDIC text format, requiring specialized conversion for modern analysis.
• Spatial coverage is limited to the satellite's orbit, with a circle of coverage radius between approximately 2500 km and 3500 km.
• The dataset's age may introduce challenges in calibration validation or integration with contemporary measurements.

Provenance

Source

NASA GES DISC, originally from the NSSDC with identifier ESAD-00248.

Collection Method

Temperatures measured by the white sensor on the Explorer-7 satellite, originally recorded on IBM 7094 machines to magnetic tapes.

Time Range

1959-11 15 to 1960-05-24 (primary mission data). Instrument operational until 1961-02-28.

Freshness

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Geography

Global coverage along the satellite orbit, with a circle of coverage radius of about 23 degrees (~2500 km) at perigee and 31.5 degrees (~3500 km) at apogee.