Title: Science Data Segment
1The NPOESS Preparatory Project (NPP) Presented
to the Engineering Colloquium NASA Goddard Space
Flight Center February 25, 2002
Dr. Robert E Murphy NPP Project Scientist Code
920 NASA GSFC
2What is NPP?
- NPP is a bridging mission that provides for the
continuation of measurement series initiated with
EOS Terra Aqua for NASAs global change
research - Climate change
- Global carbon cycle
- Global water cycle
- NPP provides risk reduction for the National
Polar-Orbiting Operational Environmental
Satellite System (NPOESS) which will continue
these measurements into the indefinite future - NPP is a joint program of NASA and the Integrated
Program Office (IPO), the tri-agency activity
that is responsible for NPOESS
3What is the NPOES Mission?
- Mission
- Provide a national, operational, polar-orbiting
environmental capability - Achieve National Performance Review savings by
converging DoD and NOAA polar satellite programs - Incorporate new technologies from NASA and others
- Incorporate, where appropriate, International
Cooperation (EUMETSAT)
4What are NASAs Earth Science Objectives?
- Discern Describe How the Global Earth System is
Changing - Identify Measure Primary Causes of Change in
the Earth System - Determine How the Earth System Responds to
Natural Human-Induced Changes - Identify the Consequences of Changes for Human
Civilization - Enable the Prediction of Earth System Changes
that will Take Place in the Future
5These Objectives are Addressed Through 23
Questions
- The NASA ESE objectives lead to 23 questions that
in turn lead to measurement requirements - NPP provides 1/2 of the measurements required
to address 10 of the 23 questions - The sounding suite (CrIS ATMS) measures
atmospheric temperature moisture profiles
many atmospheric constituents amounts - VIIRS measures many cloud aerosol properties as
well as biological physical properties of the
land ocean surface
6Discern Describe How the GlobalEarth System is
Changing
How are global precipitation, evaporation the
cycling of water changing?
How is the global ocean circulation varying on
interannual, decadal, longer time scales?
How are global ecosystems changing?
7Identify Measure Primary Causesof Change in
the Earth System
What trends in atmospheric constituents solar
radiation are driving climate change?
What are the changes in global land cover land
use, what are their causes?
8Determine How the Earth System Responds
toNatural Human-Induced Changes
What are the effects of clouds surface
hydrologic processes on Earths climate?
How do ecosystems respond to affect global
environmental change the carbon cycle?
9Identify the Consequences of Changesfor Human
Civilization
What are the consequences of land cover land
use change?
10Enable the Prediction of Earth System
Changesthat will Take Place in the Future
How can weather forecast duration reliability
be improved by new space-based observations, data
assimilation modeling?
How well can transient climate variations be
understood predicted?
11Satellite Transition Schedule(9 March 2001)
Projected End of Life based on 50 Need
CY
99
00
11
12
13
14
15
16
17
18
03
08
09
10
01
02
07
04
05
06
0530
F20
F18
F16
DMSP
0730 - 1030
F17
F19
F15
DMSP
M
POES
METOP
Local Equatorial Crossing Time
EOS AM-2
EOS AM-3
1330
N
N
L (16)
POES
Earliest Need to back-up launch
EOS PM-3
S/C Deliveries
12Satellite Transition Schedule(9 March
2001)Slopes indicate 10-90 need (NPOESS GAP 5b)
Projected End of Life based on 50 Need
CY
99
00
11
12
13
14
15
16
17
18
03
08
09
10
01
02
07
04
05
06
0530
F20
F18
F16
DMSP
0730 - 1030
F17
F19
F15
DMSP
M
POES
METOP
Local Equatorial Crossing Time
1330
N
N
L (16)
POES
Earliest Need to back-up launch
S/C Deliveries
13Satellite Transition Schedule(9 March
2001)Slopes indicate 10-90 need (NPOESS GAP 5b)
Projected End of Life based on 50 Need
CY
99
00
11
12
13
14
15
16
17
18
03
08
09
10
01
02
07
04
05
06
0530
F20
F18
F16
C3
NPOESS
DMSP
0730 - 1030
F17
F19
F15
C1 or C2
NPOESS
NPOESS
DMSP
M
POES
METOP
Local Equatorial Crossing Time
1330
N
N
C2 or C1
L (16)
NPOESS
POES
Earliest Need to back-up launch
S/C Deliveries
Earliest Availability
14NPP Carries Three Critical Sensors
- The Visible Infrared Imaging Spectroradiometer
Suite (VIIRS) extends the measurement series
initiated with the Moderate Resolution Imaging
Spectroradiometer (MODIS) on EOS Terra Aqua - Design is evolutionary from MODIS
- The Cross-track Infrared Sounder (CrIS) continues
the measurement series to be initiated with the
Atmospheric Infrared Sounder (AIRS) on EOS Aqua - Utilizes a Michelson interferometer in contrast
to AIRS, which is a spectrometer - The Advanced Technology Microwave Sounder (ATMS)
continues the measurement series initiated by the
Advanced Microwave Sounding Unit on NOAA-15 - MMIC Technology used to reduce mass, power
volume
15Operational Research Data Products
- The operational system (NPOESS) will produce
Environmental Data Records (EDRs) of geophysical
products in less than 90 minutes from acquisition - Timeliness requirement limits accuracy
consistency that can be obtained - Yesterdays weather is of limited use
- NASAs program requires maximum accuracy and
consistency over many years - Timeliness is not an issue
- NASA will produce similar geophysical products in
the form of Climate Data Records (CDRs)
16Visible Infrared Imaging Radiometer Suite (VIIRS)
- Purpose Global observations of land, ocean,
atmosphere parameters at high temporal resolution
( daily) - Predecessor Instruments AVHRR, OLS, MODIS,
SeaWiFS - Management Integrated Program Office
- StatusPhase C/D (Raytheon)
- Approach Multi-spectral scanning radiometer (22
bands between 0.4 ?m and 12 ?m) 12-bit
quantization - Swath width 3000 km
- Changes to specifics of band dynamic ranges,
bandpasses band centers being negotiated - Consideration of adding 6.7 micrometer water
vapor band to FM2 later models - CDR March 2002
17VIIRS Spectral Bands
- 22 Bands
- Two spatial resolutions
- Imagery resolution bands 370 m at nadir
- Moderate resolution bands 740 m at nadir
- Features
- 8 (Moderate) or 16 (Imagery) detectors per scan
- Bands spatially nested
- Constrained pixel growth with scan angle
- Some bands have dual gain
- Maximize dynamic range without precision
penalties
18VIIRS Optimized Bandset Supports All EDRs
19Cross-track Infrared Sounder (CrIS)
- Purpose In conjunction with ATMS, global
observations of temperature and moisture profiles
at high temporal resolution ( daily). - Predecessor Instruments HIRS, AIRS, IASI
- Management IPO
- Status Phase C/D (ITT)
- Approach Michelson interferometer (1142
channels in 3 bands (3.5 ?m gtgt 16 ?m) - Swath width 2300 km
- Co-registration with ATMS
- Second Engineering Development Unit Fall 2002
- CDR Early 2003
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21CrIS Sounding Regions
22Advanced Technology Microwave Sounder (ATMS)
- Purpose In conjunction with CrIS, global
observations of temperature and moisture profiles
at high temporal resolution ( daily). - Predecessor Instruments AMSU A1 / A2, MHS
- Management NASA
- Status Phase C/D (Aerojet)
- Approach Scanning passive microwave radiometer
(22 channels (23 GHz gtgt 183 GHz) - Swath width 2300 km
- Co-registration with CrIS
23ATMS Channel Parameters
24ATMS Sounding Regions
25Selected VIIRS Topics
- Lessons learned from SeaWiFS MODIS, advances in
technology lead to an equally capable, smaller
less complicated sensor - Spectral bands are a subset of MODIS bands
- Pixel aggregation scheme used to minimize pixel
growth - MODIS Sea Surface Temperature (SST) results offer
insight to VIIRS capability - MODIS imagery shows impact of urbanization
26Visible Infrared Imaging Spectroradiometer
(VIIRS)
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34Detector Aggregation Reduces Pixel Growth
To
to 1060km
To
VIIRS Reduces Pixel Size Along Scan Much Better
HSR, SNR Toward Nadir
AVHRR MODIS 1 km Bands 2x6km At
Edge Vs. VIIRS 1.6x1.6 km At Edge
Horizontal Sampling Interval
To
to 1060km
To
Horizontal Sampling Interval
Moderate and Imaging bands nest 2x2
35Reduced Pixel Growth Along Scan
Ratio of Off-nadir pixel to nadir pixel
1500 km
36Quality Level Best
-2 5 10 15 20 25 30 35 Co
Feb 2001
37Quality Level Best
-2 5 10 15 20 25 30 35 Co
July 2001
38MODIS Thermal vs Midwave SST in the Mediterranean
August 30, 2000
11 µm SST
4 µm SST
39Effect of Saharan Dust on SST Derivation
Thermal and Midwave SST
4
SST4
SST11
Brightness Temperature
B20
B22
B23
B31
B32
40Effect of Saharan Dust on SST Derivation
SST Difference
4
SST4 SST11
R0.531 R0.667
Spectral Aerosol Ratio
R0.443
R0.488
R0.412
R0.531
Reflectance
R0.551
R0.557
R0.678
41Northeast Corridor
Huntsville
Fall Line
42Selected CrIS/ATMS Topics
- Interferometer poses unique challenges each
interferogram is equivalent to ruling a new
grating for a spectrometer - CrIS VIIRS synergisms could lead to improved
products - Past experience points to dramatic improvements
in weather prediction
43Spectral Characteristics Of An Interferometer
- Interferometer measures the Fourier transform of
the spectrum - The spectral response function is unlocalized
has negative sidelobes - Negative energy has no physical meaning!
- Apodized spectrum is made by applying the Fourier
transform to the product of the interferogram
times an apodization function - Apparent spectral resolution is
- decreased but results are physically
- meaningful
- Choice of apodization function is
- critical to success
- CrIS will have lower effectiveresolution than
AIRS but betterS/N will compensate
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45CrIS VIIRS Synergisms Could Lead to Improved
Products
- CrIS must retrieve profiles in 50 cloudy
conditions - VIIRS cloud data needed to validate retrievals
- Interferometer may be sensitive to distribution
of clouds in the field of view - VIIRS data can support advanced algorithm
- VIIRS lacks a 6.7 micron band that MODIS has
shown to be valuable in certain conditions - Nighttime polar inversions
- CrIS can simulate the band at reduced spatial
resolution
46CrIS Must Operate in Partly Cloudy Conditions
47VIIRS Cloud Cover Needed to Validate CrIS Data
48CrIS Could be Used to Simulate VIIRS Band
MODIS 6.7 micron band not included in
VIIRS Very dry polar atmosphere makes this
region transparent MODIS has shown value of this
band for detecting polar inversions Future
VIIRS may include this band. On NPP CrIS can be
used to synthesize the band at lower resolution
49NPP Sensors will Lock-in Weather Forecast Gains
from EOS
- CrIS ATMS provide global observations of
temperature, pressure and moisture profiles at
high temporal resolution ( 2X Daily). - Atmospheric soundings will be of similar quality
(1K/km) to those being pioneered by
AIRS/AMSU/HSB on EOS Aqua - Soundings will be of radiosonde quality for input
to weather models - In US radiosondes are launched 2X daily on a
typical spacing of 500 Km - Accuracy 1.5K / 500m
- African continent, central Asia have spacing up
to 3,000 Km - Oceans have no soundings
- Current satellite soundings have accuracy 2-3
K/Km - Help fill in the gaps, but not sufficient
vertical resolution - CrIS/ATMS will have accuracy lt1K/Km
- 50 Km spacing globally
- Matches observations to model capabilities
50Typical Radiosonde Data Coverage
51A Success Story (Predicted)
- When the Advanced Microwave Sounder Unit (AMSU)
was introduced into operational systems the 5-day
forecast skill improved by 1/2 day
- Improved infrared sounding with AIRS
expected to provide 1 Full day
improvement - Benefits deployment of assets ranging from
farmers irrigation harvesting plans to
municipal storm preparedness planning - Ample evidence of 0.5 K errors in mid-US
atmospheric temperature analysis (due to
sparseness of radiosonde network) leading to 500
km (or greater) mis-location of storm
system 5 days later in europe - NPP and NPOESS will fill the gaps
- Improvement in 12 Hour forecasts also
expected - Last 2 DC area snow storms 1 correct 1
incorrect - Improvements expected
- CrIS/ATMS locks in the previous operational
mission gain of AMSU the research mission
gain of AIRS
52Summary
- NPP will provide data continuity for critical
global change measurement series initiated by EOS
Terra Aqua - These measurements will provide the core
systematic measurements needed to address the
questions in the Earth Science Enterprise
Strategic Plan - Lessons learned from EOS MODIS AIRS/AMSU have
strongly influenced the sensor algorithm
development for VIIRS CrIS/ATMS - MODIS has demonstrated major improvements over
its predecessor sensors due to the high quality
of the sensor, its careful characterization
calibration state-of-the-art algorithms - With the launch of AIRS/AMSU/HSB on Aqua
significant improvements in weather forecasting
are expected