Transcript Document

GPM Constellation Reconfiguration and Mission Status
Arthur Y. Hou
NASA Goddard Space Flight Center
[email protected]
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.
GMI
KuPR KaPR
• 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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Recent progress in sensor capabilities and retrieval algorithms
- notably
• proven capability of AMSU-B high-frequency water-vapor channels
• improved quality of AMSU-B precipitation retrievals
has enabled GPM to evolve during its formation phase
Milestones:
• Approval of GMI high-frequency capabilities in 2005
• Reconfiguration of the baseline GPM constellation to include
crossing-track microwave sounders over land
• NASA constellation satellite in a low inclination orbit to improve
near-realtime hurricane monitoring & prediction
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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
RMS errors
due to
temporal
mismatches
within 1h
observation
window for
perfect
retrievals
Sounder retrievals with
HF water vapor channels
are closer to PR than
C-S imagers without HF
between 1-10 mm/h
Lin & Hou (2006)
In GPM era most C-S imagers & X-T sounders will have HF channels
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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)
TRMM PR
Over Tropical Land (35N-35S)
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
6 Conically-Scanning
Imagers
6 C-S Imagers Plus
4 Cross-track Sounders (Over land)
(< 3h over 92% of globe)
(< 3h over 86% of globe)
Lin & Hou (2006)
Hour
GPM Core, NASA-1(40o), F18, F19
GCOM-W, Megha-Tropiques
Arthur Hou, October 23, 2006
With addition of MetOp-B, NPP,
NOAA-19, & NPOESS-C1 over land
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Passive Microwave Sensor (PMW) Characteristics in GPM Era
Constellation microwave sensor channel coverage
V – Vertical Polarization
Channel
6
GHz
10
GHz
19
GHz
23
GHz
31/36
GHz
AMSR-E
6.925
V/H
10.65
V/H
18.7
V/H
23.8
V/H
36.5
V/H
89.0 V/H
10.65 V/H
18.70 V/H
23.80 V
36.50 V/H
MADRAS
18.7 V/H
23.8 V
36.5 V/H
SSMIS
19.35 V/H
22.235 V
37.0 V/H
GMI
50-60
GHz
H – Horizontal Polarization
50.3-63.28 V/H
89/91 GHz
150/166
GHz
183/190
GHz
89.0 V/H
165.5 V/H
183.31 V
89.0 V/H
157 V/H
91.65 V/H
150 H
183.31H
89 V
157 V
183.311 H
190.311 V
87-91
164-167
183.31
MHS
ATMS
23.8
31.4
50.3-57.29
Mean Spatial Resolution (km)
Channel
6 GHz
10 GHz
19
GHz
23
GHz
31/36
GHz
AMSR-E
56
38
21
24
12
5
26
15
12
11
MADRAS
40
40
40
SSMIS
59
59
36
GMI
50-60
GHz
22
MHS
ATMS
74
74
32
89/91
GHz
150/166
GHz
183 GHz
6
6
6
10
6
14
14
14
17
17
17
16
16
16
Different center frequencies, viewing geometry, and spatial resolution must be reconciled
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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)
Retrieved - Sensor TB (K)
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
Level 1B TB Bias at non-rainy pixels
Intercalibrated Level 1C TB w.r.t. TMI
Coincident
sensor TB
calibrated to
simulated TMI TB
Courtesy
C. Kummerow
Sensor Channel (GHz)
Sensor Channel (GHz)
Using DPR+GMI on GPM Core to calibrate coincident TB’s rainy and non-rainy pixels
L1C homogenizes existing L1B for precipitation retrieval without replacing
official L1B products
An open community effort: http://mrain.atmos.colostate.edu/LEVEL1C/
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GPM Mission:
• Improve understanding of precipitation physics
• Unify a heterogeneous constellation of passive microwave sensors to provide
accurate and timely global precipitation measurements for research & applications
NASA constellation in a
low-inclination orbit
• Improved near-real time
hurricane monitoring and
prediction
GPM Core Spacecraft
• Increased sensitivity for
light rain and snow
detection
• Better overall
measurement accuracy
• Uniform calibration of
brightness temperatures
of Constellation sensors
• Detailed microphysical
information and a common
cloud database for rain &
snow retrievals from Core
& Constellation sensors
GPM Core
NASA-40o
GCOM-W
Megha-Tropiques
NOAA-19
NPP
MetOp-B
NPOESS-C1
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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
1. 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, absorptionscattering-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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Summary
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
The success of GPM will rely on
the continued support and advocacy of the community such as
IPWG!
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