Global Hydrology Resource Center (GHRC) is one of NASA's Earth Science Data Centers and is a collaboration between MSFC and the University of Alabama in Huntsville.

GPM Ground Validation Satellite Simulated Orbits
Field Campaigns: C3VP, LPVEx, MC3E, TWP-ICE

Table of Contents

Introduction
Citation
      C3VP
      LPVEx
      MC3E
      TWP-ICE
Campaign
      C3VP
      LPVEx
      MC3E
      TWP-ICE
Instrument Description
Investigators
File Naming Convention
Data Format
Contact Information

Introduction

The Global Precipitation Measurement (GPM) Ground Validation Satellite Simulated Orbits datasets are available for multiple campaigns: Light Precipitation Evaluation Experiment (LPVEx), Midlatitude Continental Convective Clouds Experiment (MC3E), Tropical Warm Pool - International Cloud Experiment (TWP-ICE), and Canadian Cloudsat/Calipso Validation Programme (C3VP). These datasets were compiled and used as part of the GPM campaign to evaluate algorithms using simulated orbital data from satellite simulators and show that algorithms are capable of meeting accuracy and precision requirements. The Satellite Simulated Orbits database takes account for the atmospheric profiles, the cloud/rain profiles, and the detailed surface/terrain information from the Cloud-Resolving Model (CRM) database. Unique geometry and antenna gain patters of each sensor (GMI imager, GMI sounder, DPR Ku, DPR Ka_MA, DPR Ka_HS) are considered. The Satellite Simulated Orbits database consists of satellite orbit parameters, geolocation of IFOV/EFOV, satellite location, and simulated L1B/L2-like parameters in satellite orbital grid. The Satellite Orbits data covers a portion of sampling right over the CRM domain. All orbital data is in netCDF3 format and contains dimensions, parameter descriptions, and parameter units. Each project's data is distributed as a separate dataset. MC3E occurred in Oklahoma, USA in 2011; LPVEX took place in Finland in 2010; C3VP experiment was held in Canada in 2007; and TWP-ICE took place in Australia in 2006.

Citation

The following examples show how to cite the use of these datasets in a publication. For more information, please see our Citing GHRC DAAC and Data page.

C3VP

Matsui, T and T. Iguchi. 2013. GPM Ground Validation Satellite Simulated Orbits C3VP [indicate subset used]. Dataset available online [http://ghrc.nsstc.nasa.gov/] from the NASA EOSDIS Global Hydrology Resource Center Distributed Active Archive Center, Huntsville, Alabama, U.S.A. doi: http://dx.doi.org/10.5067/GPMGV/C3VP/OVERPASS/DATA401

LPVEx

Matsui, T and T. Iguchi. 2013. GPM Ground Validation Satellite Simulated Orbits LPVEx [indicate subset used]. Dataset available online [http://ghrc.nsstc.nasa.gov/] from the NASA EOSDIS Global Hydrology Resource Center Distributed Active Archive Center, Huntsville, Alabama, U.S.A. doi: http://dx.doi.org/10.5067/GPMGV/MC3E/OVERPASS/DATA401

MC3E

Matsui, T and T. Iguchi. 2013. GPM Ground Validation Satellite Simulated Orbits MC3E [indicate subset used]. Dataset available online [http://ghrc.nsstc.nasa.gov/] from the NASA EOSDIS Global Hydrology Resource Center Distributed Active Archive Center, Huntsville, Alabama, U.S.A. doi: http://dx.doi.org/10.5067/GPMGV/LPVEX/OVERPASS/DATA401

TWP-ICE

Matsui, T and X. Li. 2013. GPM Ground Validation Satellite Simulated Orbits TWP-ICE [indicate subset used]. Dataset available online [http://ghrc.nsstc.nasa.gov/] from the NASA EOSDIS Global Hydrology Resource Center Distributed Active Archive Center, Huntsville, Alabama, U.S.A. doi: http://dx.doi.org/10.5067/GPMGV/TWPICE/OVERPASS/DATA401

Campaign

The Global Precipitation Measurement (GPM) mission Ground Validation (GV) campaign used a variety of methods for validation of GPM satellite constellation measurements prior to launch of the GPM Core Satellite, which launched on February 27th, 2014. The validation effort included numerous GPM-specific and joint-agency/international external field campaigns, using state of the art cloud and precipitation observational infrastructure (polarimetric radars, profilers, rain gauges, disdrometers). Surface rainfall was measured by very dense rain gauge and disdrometer networks at various field campaign sites. These field campaigns accounted for the majority of the effort and resources expended by Global Precipitation Measurement (GPM) mission Ground Validation (GV). More information about the GPM mission is available here http://pmm.nasa.gov/GPM.

C3VP

The Canadian CloudSat/CALIPSO Validation Programme (C3VP) was part of the NASA GPM Project and the Precipitation Measurement Mission (PMM); the campaign took place during the winter of 2006-2007 in the vicinity of the Centre for Atmospheric Research Experiments (CARE) operated by the Meteorological Service of Canada. More information about the C3VP campaign is available here http://pmm.nasa.gov/science/ground-validation/C3VP/.

LPVEx

The Light Precipitation Evaluation Experiment (LPVEx) took place in September and October 2010 in the Gulf of Finland to characterize the ability of CloudSat, the Global Precipitation Mission (GPM) Dual-frequency Precipitation Radar (DPR), and existing/planned passive microwave (PMW) sensors such as the GPM microwave imager (GMI) to detect light rain and evaluate their estimates of rainfall intensity in high latitude, shallow freezing level environments. The experiment leveraged in situ microphysical property measurements, coordinated remote sensing observations, and cloud resolving model simulations of high latitude precipitation systems to conduct a comprehensive evaluation of precipitation algorithms for current and future satellite platforms. The campaign will use these measurements to better understand the process of light rainfall formation at high latitudes and augment the currently limited database of light rainfall microphysical properties that form the critical assumptions at the root of satellite retrieval algorithm. More information about the LPVEx campaign is available here http://gpm.nsstc.nasa.gov/lpvex/.

MC3E

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. More information about the MC3E campaign is available here http://gpm.nsstc.nasa.gov/mc3e/.

TWP-ICE

The Tropical Warm Pool International Cloud Experiment (TWP-ICE) is one of the most complete datasets of tropical cirrus and convection observations ever collected; the campaign took place in the area around Darwin, Australia, in early 2006. The aim of the experiment was to examine convective cloud systems from their initial stages through to the decaying and thin high level cirrus and measure their impact on the environment. The experiment design includes an unprecedented array of soundings and other information to support cloud resolving and other modeling studies as well as a large range of in-situ and remotely sensed observation platforms. More information about the TWP-ICE campaign is available here http://acrf-campaign.arm.gov/twpice/.

Instrument Description

Two Cloud-Resolving Models (CRM) were used to create the Satellite Simulated Orbits datasets. For the C3VP, LPVEx, and MC3E campaigns the CRM type: WRF-SBM was used. WRF-SBM is a regional 3D cloud-resolving model with Spectra-Bin Microphysics (7-species, 43-bin) that predicts explicit melting, riming fraction in snow aggregate; land-surface is heterogeneous with terrain. For the TWP-ICE campaign CRM type: GCE-SBM was used. GCE-SBM is an idealized cloud-resolving model with Spectra-Bin Microphysics (7-species, 33-bin) that predicts explicit melting fraction in snow aggregate; surface is homogeneous (usually water).

The models were used to simulate the GPM Microwave Imager (GMI) and the Dual-frequency Precipitation Radar (DPR) instruments prior to their launch. The GMI instrument is a multi-channel, conical-scanning, microwave radiometer serving an essential role in the near-global-coverage and frequent-revisit-time requirements of GPM; this instrument also has two different viewing angles, indicated as GMI imager (10~89GHz) and GMI sounder (166~183GHz) and the data is therefore stored in two separate files. The DPR is one of the prime instruments for the GPM Core Observatory; data collected by the instrument will provide 3-dimensional observations of rain and will also provide an accurate estimation of rainfall rate. The DPR instruments (DPR Ku, Ka_MA, and Ka_HS ) have different scanning patterns and are therefore stored in three separate files.

More information about these instruments, specific to the datasets, can be found in the PI's documents Simulator_Database_V1.doc and GPM_Simulator.pptx; and information specific to the GPM mission can be found here http://pmm.nasa.gov/GPM/flight-project/DPR and here http://pmm.nasa.gov/GPM/flight-project/GMI.

Investigators

Toshihisa Matsui, Ph.D
Associate Research Scientist
Code612 NASA Goddard Space Flight Center
Greenbelt, MD, 20771

File Naming Convention

The Satellite Simulated Orbits datasets consist of satellite orbit parameters, geolocation of IFOV/EFOV and satellite location, and simulated L1B/L2-like parameters in satellite orbital grid. Orbital data covers a portion of sampling right over the CRM domain. All orbital data format is netCDF3, and it contains dimensions, parameter descriptions, and parameter units. All undefined values are set to be -999. The following file naming convention is used for the dataset files:

C3VP, LPVEx, MC3E:

wrfout_d02_YYYY-MM-DD_HHMMSS.DPR_*****.ORBITAL.TESTBED_TEL-SPHE.nc
wrfout_d02_YYYY-MM-DD_HHMMSS.GMI_**.ORBITAL.TESTBED_TEL-SPHE.nc

TWP-ICE:

GCEBN3D_TWPICE_YYYY-MM-DD_HHMMSS.DPR_*****.ORBITAL.TESTBED_SPHE.nc

Where,

wrfout_d02 = the CRM type; database made from WRF output
GCEBN3D_TWPICE = the CRM type; database made from GCE output only for the TWP-ICE campaign
YYYY-MM-DD = year, month, and day the orbital database was made
HHMMSS = time (GMT) the orbital database was made
DPR =Dual-frequency Precipitation Radar
GMI = GPM Microwave Imager
***** = indicates which DPR instrument (Ku, Ka_MA, or Ka_HS) was simulated
** = indicates which GMI instrument (imager = LF or sounder = HF) was simulated
ORBITAL.TESTBED = orbital database was created
TEL = TELSEM surface emissivity database used to compute bottom boundary of radiative transfer model
SPHE = sphere; single scattering parameters are computed under Mie assumption
.nc = netCDF file type

Data Format

Data for the GPM Ground Validation Satellite Simulated Orbits datasets is available in netCDF3 format. The orbital databases include: satellite orbit parameters, geolocation of IFOV/EFOV and satellite location, and simulated L1B/L2-like parameters in satellite orbital grid. Orbital data covers a portion of sampling right over the CRM domain. Separate datasets for each campaign are available.

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: ghrcdaac@itsc.uah.edu
Web: http://ghrc.nsstc.nasa.gov/