Nimbus-4 Satellite Ultraviolet Radiance Measurements from 1970-1977

April 1970 to May 1977 calibrated and geolocated backscattered ultraviolet radiance data from the Nimbus-4 BUV instrument, measured at 12 wavelengths between 250 and 340 nm during sunlit orbit segments. The dataset, produced by the GES DISC, contains quality flags, dark current analyses, orbital information, and housekeeping data. Data collection became increasingly sparse after a July 1972 solar array failure.

Use Cases

• Analyze long-term trends in backscattered ultraviolet radiance at specific wavelengths (e.g., 250 nm, 340 nm) for ozone research.
• Correlate radiance measurements with orbital information and quality flags to filter and validate data quality for specific time periods.
• Use geolocated radiance data from the daylit orbit portion to map historical ultraviolet reflectance patterns over Earth's surface.
• Study the impact of instrument operation changes, post-July 1972, on data sparsity and coverage, particularly in equatorial regions.

Strengths

• Data spans over 7 years from April 1970 to May 1977, providing a multi-year record.
• Contains measurements at 12 specific ultraviolet wavelengths between 250 and 340 nm.
• Includes ancillary data like quality flags, dark current analyses, and orbital information for validation.

Limitations

• Data sparsity increased significantly after a July 1972 power failure, especially in equatorial regions.
• Data is stored in its original IBM 360 binary format, which requires specialized tools for reading and processing.
• Typical orbit file size is about 70 kB, suggesting a relatively small volume of data per file.

Provenance

Source

GES DISC (Goddard Earth Sciences Data and Information Services Center), derived from the Nimbus-4 BUV instrument Primary Data Base.

Collection Method

Calibrated and geolocated backscattered ultraviolet radiances measured every 32 seconds during sunlit orbit portions, restored from original magnetic tapes.

Time Range

1970-04-10 to 1977-05-06

Freshness

Data collection ended on May 6, 1977; it is a historical archive with no updates.

Geography

Global coverage from the Nimbus-4 satellite orbit.