GPM Constellation Reconfiguration and Mission Status

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GPM Constellation Reconfiguration and Mission
Status
Arthur Y. Hou NASA Goddard Space Flight
Center arthur.y.hou_at_nasa.gov
IPWG 3rd Workshop, October 23-27, 2006 Melbourne,
Australia
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GPM is an international satellite mission to
unify and advance global precipitation
measurements
GPM advances over current capabilities

• GPM Core Spacecraft carries a dual-frequency
  radar a multi-frequency radiometer to provide
  measurements of 3-D precipitation structures and
  microphysical properties to serve as a
  precipitation physics observatory for improved
  understanding of precipitation processes and
  retrieval algorithms.
• GPM Core Spacecraft is in a 65o-inclined orbit
  to provide coincident measurements with partner
  satellites, enabling the Core radar/radiometer to
  serve as a reference standard to obtain uniformly
  calibrated global precipitation measurements from
  a heterogeneous constellation of dedicated and
  operational passive microwave radiometers.

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GPM originally conceived as a satellite mission
that provides precipitation measurements around
the globe approximately every 3 hours
by conically-scanning radiometers
3 Hour Coverage by GPM Core and 7 Constellation
Radiometers
comprising dedicated and operational
satellites GPM Core, F18, F19, GCOM-W,
Megha-Tropiques, NASA-1, Partner-1, Partner-2
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Surface Rain Retrievals from Passive Microwave
Sensors Compared with TRMM PR Over U.S.
Normalized RMS errors of TMI, AMSR-E, F13, F14,
F15 surface rain retrievals with respect to
ground measurements over U.S., and corresponding
errors for AMSU-B (15, 16, 17) and TRMM PR
0.25o instantaneous retrievals within hourly
windows against continuous surface radar gauge
measurements for JJA 2005
In GPM era most C-S imagers X-T sounders will
have HF channels
Sounder retrievals with HF water vapor channels
are closer to PR than C-S imagers without HF
between 1-10 mm/h
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Surface Rain Retrievals from Passive Microwave
Sensors Over Land
0.25o instantaneous retrievals within hourly
windows (Jan-Dec 2005)
Over U.S. (South of 35N)
Over Tropical Land (35N-35S)
TRMM PR
RMS errors due to temporal mismatches within 1h
observation window for perfect
retrievals
Lin Hou (2006)
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Average Revisit Times by Passive Microwave
Sensors in GPM Era
Lin Hou (2006)
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Passive Microwave Sensor (PMW) Characteristics
in GPM Era
V Vertical Polarization H Horizontal
Polarization

• Constellation microwave sensor channel coverage
• Mean Spatial Resolution (km)

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GPM provides a consistent framework to unify a
heterogeneous constellation of PMW sensors (both
C-S imagers and X-T sounders)

• By making combined use of DPR GMI on GPM Core
  Spacecraft to provide
• - a uniform calibration of brightness
  temperature measurements and
• - a common cloud/hydrometeor database for
  precipitation retrievals

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• Improve understanding of precipitation physics
• Unify a heterogeneous constellation of passive
  microwave sensors to provide accurate and timely
  global precipitation measurements for research
  applications

GPM Mission
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GPM Ground Validation for Improving Satellite
Simulators, Retrieval Algorithms, Hydrological
Applications

• Statistical validation sites for direct
  assessment of GPM satellite surface precipitation
  products
• Co-located with existing or upgraded national
  network (NEXRAD etc.) and dense gauge networks to
  identify and resolve significant discrepancies
  between the national network and satellite
  estimates
• Leveraging off national networks of partnership
  countries and international scientific
  collaboration for regional and global assessments
  
• Precipitation process sites for improving
  understanding and modeling of precipitation
  physics in physical and radiance spaces for
  satellite retrieval algorithm refinements
• Continental tropical, mid- and high-latitude
  sites (including orographic/coastal sites and
  targeted sites for resolving discrepancies
  between satellite algorithms)
• Oceanic tropical and mid-latitude sites
• Aircraft measurements
• Integrated hydrological sites for improving
  hydrological applications
• Co-located with existing watersheds maintained by
  other US agencies and international research
  programs to use hydrological basins as an
  integrated measure of the quality of
  precipitation products
• International GPM GV
  partnership opportunities

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Joint CloudSat/CALIPSO/GPM Field Campaign

• GPM Participation in the Canadian
  CloudSat/Calipso Validation Program
• Winter 2006-2007
• GPM hardware contributions
• an Advanced Multi-frequency (Ka-Ku-W) radar
  (UMass)
• a 2D video disdrometer (CSU)
• GSFC Parsvels for measuring hydrometeor numbers,
  sizes (maximum width), type, and fall speeds
• 2. Collection of data sets for development of GPM
  snowfall detection and estimation algorithms
• Develop models that convert microphysical
  properties (snow size, shape distributions,
  density, ice-air-water ratio) to radiative
  properties (asymmetry factor, absorption-scatterin
  g-backscatter coefficients)
• Relate radiative properties to microwave
  radiances and radar reflectivities observed by
  GPM instruments
• Combine satellite, aircraft and ground
  measurements for GPM GMI and DPR algorithm
  validation
• Support Cloud-Resolving Model (CRM) microphysics
  validation in cold-region simulations

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GPM Mission Status

• NASA and JAXA have signed an agreement to jointly
  formulate the GPM mission with the following
  assumptions
• JAXA to provide a Dual-frequency Precipitation
  Radar (DPR) for the GPM Core spacecraft and
  launch services for the Core spacecraft
• KuPR and KaPR engineering model under development
  testing
• NASA to provide two GPM Microwave Imager (GMI)s,
  the Core spacecraft, a constellation spacecraft
  associated launch services
• GMI in development by Ball Aerospace Technology
  Corporation
• Joint NASA and industry development of Core
  Spacecraft underway
• Selection of a new NASA/Precipitation Missions
  Science Team (November 2006)
• GPM Core spacecraft launch circa 2013
• Constellation partnership development
• Partnerships in formulation JAXA, NOAA, DoD
• Partnerships under discussion AEB (Brazil)
• Future opportunities ISRO(India)/CNES(France),
  ESA, EUMETSAT
• GPM Planning Workshops
• 6th GPM International Planning Meeting to be held
  6-8 November 2005 in Annapolis, MD, USA.
• 2nd GPM International Ground Validation Workshop
  held in September 2005 in Taipei, Taiwan. 3rd GV
  Workshop is under planning for 2007.

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Recent National Research Council Recommendations

• The (NASA) Global Precipitation Measurement
  (GPM) mission should be launched without further
  delays.
• Earth Science and Applications from Space
  Urgent Needs and Opportunities to Serve the
  Nation, National Academies Press, Washington, DC,
  2005

NOAA takes over the operation of the GPM Core
satellite from NASA five years after
launch. Develop a GPM follow-on NOAA program...
as U.S. components of a continuing and evolving
international constellation of satellites within
the WMO ... for satellite-based global
precipitation measurements. Report
of NRC/BASC Committee on the Future of
Precipitation Missions, September, 2006
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• The GPM Mission will unify and advance
  global precipitation
  measurements by providing
• advanced microwave sensors (DPR GMI)
• a consistent framework for inter-satellite
  calibration
• science teams for algorithm development, ground
  validation, and improved use of precipitation
  data in research applications

Summary
The success of GPM will rely on
the continued
support and advocacy of the community such
as IPWG!