Science Data Segment

1
The 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
2
What 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

3
What 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)

4
What 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

5
These 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

6
Discern 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?
7
Identify 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?
8
Determine 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?
9
Identify the Consequences of Changesfor Human
Civilization
What are the consequences of land cover land
use change?
10
Enable 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?
11
Satellite 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
12
Satellite 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
13
Satellite 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
14
NPP 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

15
Operational 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)

16
Visible 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

17
VIIRS 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

18
VIIRS Optimized Bandset Supports All EDRs
19
Cross-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

20
(No Transcript)
21
CrIS Sounding Regions
22
Advanced 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

• CDR April 2002

23
ATMS Channel Parameters
24
ATMS Sounding Regions
25
Selected 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

26
Visible Infrared Imaging Spectroradiometer
(VIIRS)
27
(No Transcript)
28
(No Transcript)
29
(No Transcript)
30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34
Detector 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
35
Reduced Pixel Growth Along Scan
Ratio of Off-nadir pixel to nadir pixel
1500 km
36
Quality Level Best
-2 5 10 15 20 25 30 35 Co
Feb 2001
37
Quality Level Best
-2 5 10 15 20 25 30 35 Co
July 2001
38
MODIS Thermal vs Midwave SST in the Mediterranean
August 30, 2000
11 µm SST
4 µm SST
39
Effect of Saharan Dust on SST Derivation
Thermal and Midwave SST
4
SST4
SST11
Brightness Temperature
B20
B22
B23
B31
B32
40
Effect 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
41
Northeast Corridor
Huntsville
Fall Line
42
Selected 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

43
Spectral 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

44
(No Transcript)
45
CrIS 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

46
CrIS Must Operate in Partly Cloudy Conditions
47
VIIRS Cloud Cover Needed to Validate CrIS Data
48
CrIS 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
49
NPP 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

50
Typical Radiosonde Data Coverage
51
A 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

52
Summary

• 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