GPM Ground Validation High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) MC3E
Table of Contents
Introduction
The High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) is a dual-frequency (Ka- and Ku-band) conical scan system, configured with a nadir viewing antenna on the high-altitude (20 km) NASA ER-2 aircraft. It provides calibrated reflectivity and unfolded Doppler velocity. These dual-frequency radar measurements have similar frequencies to the GPM Dual-frequency Precipitation Radar (DPR).
Campaign
The Midlatitude Continental Convective Clouds Experiment (MC3E) took place in central Oklahoma during the April-June 2011 period. The experiment was a collaborative effort between the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility and the National Aeronautics and Space Administration's (NASA) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The field campaign leveraged the unprecedented observing infrastructure currently available in the central United States, combined with an extensive sounding array, remote sensing and in situ aircraft observations, NASA GPM ground validation remote sensors, and new ARM instrumentation purchased with American Recovery and Reinvestment Act funding. The overarching goal was to provide the most complete characterization of convective cloud systems, precipitation, and the environment that has ever been obtained, providing constraints for model cumulus parameterizations and space-based rainfall retrieval algorithms over land that had never before been available.
Further details on GPM MC3E are available at http://gpm.nsstc.nasa.gov/mc3e/. Information on MC3E ARM is available at http://campaign.arm.gov/mc3e/.
Instrument Description
During MC3E, HIWRAP was modified with a new dual-frequency nadir pointing antenna designed for the ER-2. For each radar frequency (Ku- or Ka-band), one of three pulse sequences were used: (2, 20) microseconds, (2, 20, 2) microseconds, or (20, 2) microseconds. Each of the pulses had a slightly different center frequency so that they could be separated by the digital receiver. The 20 microsecond chirp pulse is the main return of interest. The first short pulse is used to obtain returns near the radar in the "blind" zone of the chirp pulse. The second short pulse is used to obtain returns near the surface since strong surface returns contaminated the near surface rain signal through the pulse compression range side lobes in the chirp channel. The reflectivity from the chirp channel has about 8 to 9 dB higher sensitivity than that of short pulses. Because of surface clutter in the chirp channel range side lobes, the reflectivity from the chirp channel was replaced with that from the second short pulse beyond 16.425 km range from the radar. This works well for most of the situations except in regions where the sensitivity from the short pulse is below the minimum detectable reflectivity and the chirp return is detectable. Further details on the HIWRAP instrument are found in the document HIWRAP_data_mc3e_v0.docx.
Investigators
Gerald Heymsfield
NASA/Goddard Space Flight Center
Mesoscale Atmospheric Process Branch
Greenbelt, MD 20771
Lin Tian
NASA/Goddard Space Flight Center
Mesoscale Atmospheric Process Branch
Greenbelt, MD 20771
Lihua Li
NASA/Goddard Space Flight Center
Mesoscale Atmospheric Process Branch
Greenbelt, MD 20771
File Naming Convention
Data and browse files are of the form:
mc3e_hiwrap_yyyymmdd_hhmmss-hhmmss.nc
mc3e_hiwrap_yyyymmdd_hhmmss-hhmmss.gif
where
mc3e = Midlatitude Continental Convective Clouds Experiment
hiwrap = High Altitude Imaging Wind and Rain Airborne Profiler
yyyymmdd = year, month and day
hhmmss = hour, minutes and seconds (15 seconds earlier than the data due to the GPS system)
nc = network Common Data Form
gif = Graphics Interchange Format
Data Format
The GPM Ground Validation High Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP) MC3E dataset consists of netCDF (.nc) files and images (.gif). Measurements included within the data files are merged pulse and chirp radar reflectivity profiles at 13.9 and 33.7 GHz. Additional details on the file naming convention and data format are found in the document HIWRAP_data_mc3e_v0.docx.
Citation
Our data sets are provided through the NASA Earth Science Data and Information System (ESDIS) Project and the Global Hydrology Resource Center (GHRC) Distributed Active Archive Center (DAAC). GHRC DAAC is one of NASA's Earth Observing System Data and Information System (EOSDIS) data centers that are part of the ESDIS project. ESDIS data are not copyrighted; however, in the event that you publish our data or results derived by using our data, we request that you include an acknowledgment within the text of the article and a citation on your reference list. Examples for general acknowledgments, data set citation in a reference listing, and crediting online web images and information can be found at: http://ghrc.nsstc.nasa.gov/uso/citation.html
References
G.M. Heymsfield, J. Carswell, High Altitude Imaging Wind and Rain
Radar (HIWRAP). , NASA Science Technology Conference 2008
(NSTC2008).
Lihua Li; Heymsfield, G.; Carswell, J.; Schaubert, D.; McLinden, M.; Vega, M.; Perrine, M.; "Development of the NASA High-Altitude Imaging Wind and Rain Airborne Profiler," 2011 IEEE Aerospace Conference, pp. 1 - 8.
Lihua Li; Heymsfield, G.; Carswell, J.; Schaubert, D.; Creticos, J.; Vega, M.; "High-Altitude Imaging Wind and Rain Airborne Radar (HIWRAP)," IEEE International Geoscience and Remote Sensing Symposium, 2008. IGARSS 2008. Vol. 3, pp. III - 354 to III - 357.
Heymsfield G, Tian L, Heymsfield A, Li L, Guimond S. Characteristics of Deep Tropical and Subtropical Convection from Nadir-viewing High-altitude Airborne Doppler Radar. J. Atmos. Sci. 2010;67 (2):285-308.
Tian L, Heymsfield G, Li L, Srivastava R. Properties of Light Stratiform Rain Derived from 10- AND 94-GHZ Airborne Doppler Radars Measurements. J. Geophys. Res.-Atmos. 2007;112 (D11):12.
Contact Information
To order these data or for further information, please contact:
Global Hydrology Resource Center
User Services
320 Sparkman Drive
Huntsville, AL 35805
Phone: 256-961-7932
E-mail: support-ghrc@earthdata.nasa.gov
Web: http://ghrc.nsstc.nasa.gov/
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