TIROS-3L1FMRT: 1961 Satellite Radiometer Measurements

Five channels of infrared and visible radiance data were collected by the TIROS-3 satellite's Medium-Resolution Scanning Radiometer for approximately two and a half months after its launch on July 12, 1961. Each file contains measurements from one orbit, expressed as equivalent blackbody temperature or effective radiant emittance, with a 55 km footprint at nadir. This dataset represents an early, recovered record of Earth's radiation from the Final Meteorological Radiation Tapes (FMRT).

Use Cases

• Analyzing early atmospheric water vapor patterns based on Channel 1 (6.0-6.5 µm) data.
• Studying historical reflected solar radiation using Channel 3 (0.2-6.0 µm) measurements.
• Comparing terrestrial radiation in the 8.0-30 µm range from Channel 4 across different orbits.
• Investigating instrument degradation over time, as response characteristics for all channels degraded rapidly.
• Tracing ground coverage patterns (elliptical, parabolic, or hyperbolic) caused by the instrument's rotation.

Strengths

• Provides a specific, early temporal snapshot: data collection began on a known date (July 12, 1961).
• Contains detailed sensor specifications, including five distinct spectral channels and a defined 55 km nadir footprint.
• Represents recovered historical data from original IBM 7094 tapes, preserving a unique record.
• Data usability for each channel is explicitly defined up to specific orbit numbers (e.g., Channel 5 up to orbit 300).

Limitations

• Critical metadata is missing: row count, file size, and column structure are unknown across all sources.
• Data is archived in a proprietary, legacy IBM 36-bit binary TAP format, creating a significant access barrier.
• The greatest uncertainty in measurements is noted as an apparent shift in the zero radiation level, affecting accuracy.
• Sources conflict on the 'last updated' date (1961 vs. 2026), creating provenance ambiguity.

Provenance

Source

NASA Goddard Space Flight Center, Principal Investigator Joseph D. Barksdale; archived by GES DISC.

Collection Method

Recovered from original Final Meteorological Radiation Tapes (FMRT) written on IBM 7094 machines.

Time Range

Approximately two and a half months starting July 12, 1961.

Freshness

2026-04-09 21:45:02.584653

Geography

Global coverage from the TIROS-3 satellite orbit.