TRMM_baseUW: Ground Radar Reflectivity Grids for Satellite Validation

University of Washington TRMM Ground Validation products provide single-level, 150x150 km cartesian grids with 2 km resolution, derived from the lowest sweep of ground-based radar. These quality-controlled grids, generated via NCAR SPRINT interpolation, are a core component for validating precipitation measurements from the TRMM satellite. Data collection focuses on four primary sites: Darwin, Australia; Houston, Texas; Kwajalein, Republic of the Marshall Islands; and Melbourne, Florida.

Use Cases

• Validating TRMM satellite-derived precipitation estimates based on ground-based radar reflectivity grids.
• Analyzing rain rate and drop size distribution (DSD) using data from collocated rain gauges and disdrometers.
• Comparing precipitation patterns across different climatic regions using data from the four primary GV sites.
• Studying interpolation methods for radar data based on the documented NCAR SPRINT algorithm output.

Strengths

• Data is part of a structured, multi-instrument Ground Validation (GV) effort for the TRMM satellite project.
• Provides high-resolution (2 km) cartesian grids with a defined horizontal extent (150x150 km).
• Collection includes long-term measurements from a network of instruments (radar, gauges, disdrometers) at four primary sites and NASA Wallops.

Limitations

• Critical metadata conflicts exist: 'last updated' dates are inconsistent (2003 vs. 2026) across platforms.
• Column names and dataset size (rows, file size) are not provided in any source.
• Documentation notes a known quirk in the netCDF files where 'alt' represents elevation angle and 'z_spacing' is meaningless.

Provenance

Source

National Aeronautics and Space Administration (NASA), University of Washington

Collection Method

Output of NCAR SPRINT interpolation of the lowest sweep of ground-based radar (1C51UW), combined with data from rain gauges and disdrometers.

Time Range

null

Freshness

Last updated date is conflicting: one source states 2003-12-31, another states 2026-04-09.

Geography

Four primary sites: Darwin, Australia; Houston, Texas; Kwajalein, Republic of the Marshall Islands; Melbourne, Florida. Additional data from NASA Wallops Flight Facility (WFF).