FIFE Gamma Ray Data: Airborne Soil Moisture Measurements

24 flight lines of natural terrestrial gamma radiation data were collected to estimate soil moisture as part of the FIFE experiment. A time-series of airborne measurements, calibrated with ground-based data, achieved an average RMS error of approximately 2.5% soil moisture for flight line segments. The data provides a validated, airborne-derived record of soil moisture content to a depth of 20 cm.

Use Cases

• Validating satellite-derived soil moisture products using an independent airborne measurement technique.
• Calibrating gamma radiation attenuation models for soil moisture estimation.
• Analyzing temporal changes in soil water content across a network of flight lines.
• Studying the relationship between soil density and gamma flux attenuation.

Strengths

• Includes a direct, quantitative validation against ground measurements, with an average RMS error of approximately 2.5% soil moisture.
• Covers a network of 24 distinct flight lines, providing spatial coverage for the study area.
• Represents a time-series, enabling analysis of soil moisture dynamics.

Limitations

• Column names and precise data structure are unknown, limiting immediate usability.
• Metadata conflicts exist: the last updated date is listed as both 1989-08-10 and 2026-04-10.
• The dataset's size and row count are not specified in any source.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Airborne data acquisition designed to accumulate and store spectral gamma radiation data along flight lines, calibrated once with ground-based soil moisture measurements.

Time Range

1989 (inferred from last updated date on NASA Earthdata)

Freshness

1989-08-10 23:59:59.999000

Geography

FIFE experiment area (specific location not detailed)