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    • TRMM Precipitation Radar Power and Reflectivity L1C 1.5 hours V7 (TRMM_1C21) at GES DISC

    Metadata Updated: April 10, 2025

    The TRMM Precipitation Radar (PR), the first of its kind in space, is an electronically scanning radar, operating at 13.8 GHz that measures the 3-D rainfall distribution over both land and ocean, and defines the layer depth of the precipitation.

    The 1C21 calculates the effective radar reflectivity factor at 13.8 GHz without any propagation loss (due to rain or any other atmospheric gas) correction (Zm). Therefore, the Zm value can be calculated just by applying a radar equation for volume scatter with PR system parameters. The noise-equivalent Zm is about 21 dBZ. Through the subtraction of the system noise, the Zm value as small as 16 or 18 dBZ are still usable although the data quality is marginal. In 1C21, all echoes stored in 1B21 are converted to "dBZ" unit. This is not relevant for "non-rain" echo; however, this policy is adopted so that the 1B21 and 1C21 product format should be as close as possible except for the following points:
    - Radar quantity is Zm in dBZ unit instead of received power (dBm). - Data at echo-free range bins judged in 1B21 are replaced with a dummy value.

    Changes in horizontal resolution resulting from the TRMM boost that occurred on 24 August 2001:

    Pre-Boost (before 7 August 2001): Temporal Resolution: 91.5 min/orbit ~ 16 orbits/day; Swath Width: 215 km; Horizontal Resolution: 4.3 km

    Post-Boost (after 24 August 2001): Temporal Resolution: 92.5 min/orbit ~ 16 orbits/day; Swath Width: 247 km; Horizontal Resolution: 5.0 km

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

    Downloads & Resources

    Dates

    Metadata Created Date November 12, 2020
    Metadata Updated Date April 10, 2025

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date November 12, 2020
    Metadata Updated Date April 10, 2025
    Publisher NASA/GSFC/SED/ESD/GCDC/GESDISC
    Maintainer
    Identifier C1282110521-GES_DISC
    Data First Published 2011-07-01
    Language en-US
    Data Last Modified 2025-03-31
    Category TRMM, geospatial
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id 9f407b92-4bd6-4b41-90d7-1ed18de1fc5e
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://cmr.earthdata.nasa.gov:443/search/concepts/C1282110521-GES_DISC.html
    Metadata Type geospatial
    Old Spatial -180.0 -38.0 180.0 38.0
    Program Code 026:001
    Source Datajson Identifier True
    Source Hash 2dca8c0d95298d9905d11cdb43a5e018840c207635e2e3b45cb8abd2ac328835
    Source Schema Version 1.1
    Spatial
    Temporal 1997-12-07T00:00:00Z/2015-04-01T23:59:59.999Z

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