Ginga LAC Mode Catalog: X-ray Astronomy Observations from 1987-1991

The Ginga LAC Mode Catalog contains selected information from the Large Area Counter aboard the Japanese Ginga X-ray astronomy satellite. The mission operated from 5 February 1987 to November 1991, collecting data in a circular orbit with a 96-minute period. This catalog was prepared by NASA HEASARC from data provided by the Institute of Space and Astronautical Science in Japan.

Use Cases

• Analyzing X-ray source variability based on observation frames of 4, 32, or 128 seconds.
• Studying instrument configuration changes based on BITRATE, LACMODE, DISCRIMINATOR, or ACS MONITOR parameters.
• Mapping observation sequences and satellite attitude using the related GINGALOG database.
• Extracting detailed FITS files for spectral or temporal analysis of specific celestial targets.

Strengths

• Data covers a defined mission period from February 1987 to November 1991.
• Catalog structure tracks changes in four specific instrument parameters (BITRATE, LACMODE, DISCRIMINATOR, ACS MONITOR).
• Duplicate entries were removed in a June 2019 update by NASA HEASARC.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Data is historical, with the mission ending in 1991.

Provenance

Source

National Aeronautics and Space Administration (NASA HEASARC), from data provided by the Institute of Space and Astronautical Science (ISAS) in Japan.

Collection Method

Prepared from LAC dump files sent to NASA/GSFC, with entries created when key instrument parameters changed.

Time Range

1987-02-05 to 1991-11

Freshness

Catalog metadata was last updated on 2026-03-13.

Geography

Space-based observations from a satellite in a circular orbit (apogee 670 km, perigee 510 km, 31-degree inclination).