CGMS-41, NOAA-WP-10
Prepared by
F. Weng and M. Goldberg
Agenda Item: II/2
Discussed in WG-II
NOAA REPORT ON SUOMI NATIONAL POLAR ORBITING
PARTNERSHIP (NPP) CALIBRATION AND VALIDTAION
RESULTS
Summary of the Working Paper
The Suomi NPP (SNPP) satellite was launched successfully on October 28, 2011
and is a pathfinder for the future US Joint Polar Satellite System (JPSS) operational
satellite series. The primary objectives of the SNPP mission provide a continuation
of the group of Earth system observations initiated by the Earth Observing System
Terra, Aqua, and Aura missions; and prepare the operational forecasting community
with pre-operational risk reduction, demonstration, and validation for selected JPSS
instruments and ground processing data systems. The SNPP satellite is now flying
with the following five instruments: Visible/Infrared Imager/Radiometer Suite
(VIIRS), Cross-track Infrared Sounder (CrIS), Advanced Technology Microwave
Sounder (ATMS, Ozone Mapping and Profiler Suite (OMPS) and Cloud and Earth
Radiant Energy System (CERES). The SNPP instruments are now undergoing a
period of intensive calval and the instrument on-orbit performances are stable and
the post-launch results all meet or exceed the specifications. The SNPP SDR
products have reached the provisional version level at which users can order the
data from NOAA archival and perform in-depth scientific research. Also, ATMS
and CRIS data have been operationally assimilated into global and regional forecast
models and a suite of EDR products are generated from the NPP ground system and
NOAA processing system. During the intensive calval, the SDR teams have
developed many innovative techniques for characterizing the instrument
performance and improving the bias corrections. Numerous SDR processing bugs
are fixed and the data quality flags are corrected and monitored at NOAA
instrument long-term monitoring system. JPSS SDR and EDR teams led by STAR
have completed critical SNPP calval tasks and the most recent SNPP calval results
will be reported in the JGR-Atmospheres Special Issues
CGMS-41, NOAA-WP-10
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INTRODUCTION
The Suomi NPP (SNPP) satellite was launched successfully on October 28, 2011 and is a
pathfinder for the future US Joint Polar Satellite System (JPSS) operational satellite series.
The primary objectives of the SNPP mission provide a continuation of the group of Earth
system observations initiated by the Earth Observing System Terra, Aqua, and Aura missions;
and prepare the operational forecasting community with pre-operational risk reduction,
demonstration, and validation for selected JPSS instruments and ground processing data
systems. The SNPP satellite is now flying with the following five instruments: 1)
Visible/Infrared Imager/Radiometer Suite (VIIRS) has multi-band imaging capabilities to
support the acquisition of high-resolution atmospheric imagery and generation of a variety of
applied products including visible and infrared imaging of hurricanes and detection of fires,
smoke, and atmospheric aerosols. 2) Cross-track Infrared Sounder (CrIS) is the the first in a
series of advanced operational sounders that provide more accurate, detailed atmospheric
temperature and moisture observations for weather and climate applications. 3) Advanced
Technology Microwave Sounder (ATMS) operates in conjunction with the CrIS to profile
atmospheric temperature and moisture. Higher (spatial, temporal and spectral) resolution and
more accurate sounding data from CrIS and ATMS support continuing advances in data
assimilation systems and NWP models to improve short- to medium-range weather forecasts.
4) Ozone Mapping and Profiler Suite (OMPS) measures the concentration of ozone in the
atmosphere, providing information on how ozone concentration varies with altitude. Data
from OMPS continue three decades of climate measurements of this important parameter used
in global climate models. The OMPS measurements also fulfil the U.S. treaty obligation to
monitor global ozone concentrations with no gaps in coverage. 5) Cloud and Earth Radiant
Energy System (CERES) seeks to develop and improve weather forecast and climate models
prediction, to provide measurements of the space and time distribution of the Earth's
Radiation Budget components. The observations from CERES are essential to understanding
the effect of clouds on the energy balance (energy coming in from the sun and radiating out
from the earth), which is one of the largest sources of uncertainty in our modelling of the
climate. The SNPP instruments are now undergoing a period of intensive calval and the
instrument on-orbit performances are stable and the post-launch results all meet or exceed the
specifications. The SNPP SDR products have reached the provisional level at which users can
order the data from NOAA archival and perform in-depth scientific research. NOAA is in
charge of calibration of four SNPP instruments: ATMS, CRIS and VIIRS and OMPS. The
critical SNPP calval tasks have been completed and the most recent calval results will be
reported in following sections.
.
2. Suomi NPP Instrument Calibration
Suomi NPP carries five instruments on board. The calibration tasks of four instruments
(ATMS, CrIS, VIIRS and OMPS) are conducted by JPSS SDR science teams led by NOAA
STAR while those for CERES are performed bt NASA Langley science team. Currently, all the
SDR/EDR products from four instruments have reached the provisional level of data quality and
they will be reaching a validated maturity in early 2014. At the provisional maturity level, the
user community from research and operations are encouraged to use the data for experiments and
publications, and participate in the quality assurance and validation of the products while SDR
science teams continue making incremental product improvements. The calibration accuracy and
the instrument sensitivity of ATMS are well characterized and within specification. An algorithm
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CGMS-41, NOAA-WP-10
is developed for converting from the antenna to sensor brightness temperatures. During the
SNPP intensive calval, ATMS was pitched over to observe the cold space radiation. This unique
data set was used for diagnostics of ATMS scan-angle dependent bias and for scan-to-scan
variation. CrIS is a first Fourier transform Michelson interferometer on board the US weather
satellite and it measures three infrared spectral bands from 650 to 1095, 1210 to 1750 and 2155
to 2550 cm-1 with spectral resolutions of 0.625, 1.125 and 2.5 cm-1. CrIS requires an accurate
spectral calibration with an uncertainty specification of 10 ppm (part per million). The on-board
CrIS spectral calibration uncertainty is proven to be less than 2 ppm. The uncertainty of CrIS
radiometric calibration is about 0.45%, 0.58%, and 0.77% for the longwave, midwave, and
shortwave bands, respectively (Tobin et al) and the total instrument sensitivity or NEdN
estimated from internal calibration target, deep space and earth scene agree very well and meet
specifications, except for MWIR FOV7 which is slightly out of specification. VIIRS has 22
spectral bands covering the spectrum between 0.412 μm and 12.01 μm, including 16 moderate
resolution bands (M-bands) with a spatial resolution of 750 m at nadir, 5 imaging resolution
bands (I-bands) with a spatial resolution of 375 m at nadir, and 1 day-night band (DNB) with a
near-constant 750 m spatial resolution throughout the scan. After correcting prelaunch pointing
and alignment measurements, VIIRS geolocation error is about 80 meters. The calibration of
VIIRS reflective solar bands (RSB) requires solar diffuser (SD) and solar diffuser stability
monitor (SDSM). The monitoring and updating of calibration coefficients scaling factor (Ffactor) for both RSB and thermal emissive bands (TEB) and the slope of SDSM reflectivity (Hfactor) are critical for a high quality of VIIRS imagery products. Due to the degradation of
VIIRS rotating telescope assembly, VIIRS F-factor requires frequent updates and the relative Ffactor is compared with the value from VIIRS roll-maneuver of lunar observations. With SNPP
yaw maneuver data, SDSM screen transmission function can be updated to better capture the fine
structures of vignetting function. OMPS is a three instrument suite including OMPS Limb
Profiler, Nadir Profiler and Mapper. For OMPS nadir mapper (NM), limb (NL) and profiler
(NP), the detector signal to noise ratio, sensor signal-to-noise ratio meets the system requirement.
Detector gain and bias performance trends are generally stable. System linearity performance
exhibits excellent stability and is highly consistent with the prelaunch values.
NOAA first sponsored SNPP ER-2 airborne campaign occurred during May 2011. The NASA
ER-2 carries aircraft validation sensors and data is collected for both SDR and EDR validation.
The SDR validation is performed as the airplane flies under Suomi NPP sensors. The remote
sensing instruments flying aboard the May ER-2 flights include: the National Polar-orbiting
Operational Environmental Satellite System (NPOESS) Airborne Sounding Testbed
Interferometer (NAST-I) operated by NASA Langley Research Center in Hampton, Va.;
NPOESS Airborne Sounding Testbed Microwave (NAST-M) operated by Massachusetts
Institute of Technology Lincoln Laboratory in Lexington, Mass.; Scanning High Resolution
Interferometer Sounder (S-HIS) operated by the University of Wisconsin-Madison; The
MODIS/ASTER Airborne Simulator (MASTER) which was developed for the Advanced
Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Moderate Resolution
Imaging Spectroradiometer (MODIS) projects, operated by NASA Ames Research Center,
Moffett Field, Calif.; and Airborne Visible Infrared Imaging Spectrometer (AVIRIS) operated by
NASA Jet Propulsion Laboratory, Pasadena, Calif. Most of the aircraft instruments are tied to
NIST traceable standards, thereby providing absolute calibration for SNPP instruments for
improved climate applications. Long-term time series of products derived from SNPP can now
be tied (traced) to SI absolute measurements thereby providing absolution calibration to SNPP
instruments –particularly the CrIS instrument.
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CGMS-41, NOAA-WP-10
3. Suomi NPP EDR Validation
The primary products generated from SNPP instruments are listed in the following Table 1.
Since NASA is responsible for developing CERES EDR products with its own version control
and schedule, the EDR from this instrument is not included in the table. Also, the majority of
papers are developed to the validation of EDR that have higher maturity levels and higher
priority. IDPS (Interface Data Processing Segment) daytime SST algorithm derives more than
60% of retrievals in meeting the accuracy requirement of 0.2K and performs reasonably well,
comparing with other SST algorithms. The CrIS and ATMS SDR products are used in Cross
Track Infrared and Microwave Sounding Suite (CrIMSS) algorithm to retrieve atmospheric
vertical temperature, moisture, and pressure profiles. The CrIMSS algorithm is performing well
and the products are meeting the requirements as expected for different categories (land, sea, and
coast) and for different regimes. Ozone environmental data records from OMPS are compared to
those from other satellite instrument and ground-based products. The initial performance is good
with total ozone within ±3% of correlative measurements and ozone profiles within ±5% in the
stratosphere. The active fire product is also derived from the VIIRS M13 and M15 bands which
have a spatial resolution of 750 meters in nadir. A visual comparison of VIIRS active fire pixels
with MODIS products show their consistency under a clear-sky land condition.
4. References
Cao, C., X. Xiong, F., Deluccia, F. Weng, 2012, Early On-orbit Performance of the Visible
Infrared Imaging Radiometer Suite (VIIRS) onboard the Suomi National Polarorbiting Partnership (SNPP) Satellite, in press
Weng, F., X. Zou, X. Wang, S. Yang, M. Goldberg, 2012: Introduction to Suomi NPP ATMS
for NWP and Tropical Cyclone Applications, J. Geophys. Res.,
doi:10.1029/2012JD018144
ACKNOWLEDGEMENTS
We would like to thank the JPSS SDR and EDR teams for dedicated support to the NPP postlaunch cal/val. This work is funded by the JPSS program office. The manuscript contents are
solely the opinions of the authors and do not constitute a statement of policy, decision, or
position on behalf of NOAA or the U.S. government.
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CGMS-41, NOAA-WP-10
Table 1. SNPP SDR and EDR priority as defined by NOAA level 1 Requirement Documents
(Level 1D), the date for beta (β), provisional (p) and validated (v) maturity level.
ATMS SDR
1
β-Date
2/10/2012
CrIS SDR
1
5/2/2012
2/13/2013
2013
VIIRS SDR
1
5/2/2012
3/13/2013
2013
VIIRS EDR Imagery (not NCC)
1
5/30/2012
2/20/2013
2013
VIIRS EDR NCC Imagery
1
10/24/2012
2013
2013
ATMS TDR
1
12/10/2010
2/6/2013
2013
VIIRS EDR Ocean Color/Chlorophyll (OCC)
2
1/16/2013
2013
2013
VIIRS EDR Sea Surface Temperature (SST)
2
2/27/2013
2013
2013
OMPS SDR Nadir Profile (NP)
3
3/7/2012
3/12/2013
2013
OMPS SDR Nadir Total Column Mapper (TC)
3/7/2012
3/12/2013
2013
CrIMMS EDR Atmospheric Vertical Moisture Profile (AVMP)
3
3
8/8/2012
3/27/2013
2013
CrIMMS EDR Atmospheric Vertical Temperature Profile (AVTP)
3
8/8/2012
3/27/2013
2013
CrIS IP Infrared Ozone Profile (will be EDR for J1)
3
8/8/2012
3/27/2013
2013
OMPS IP Ozone - Nadir Profile (NP) (will be EDR for J1)
3
7/25/2012
4/17/2013
2013
OMPS EDR Ozone - Total Column (TC)
VIIRS EDR Cloud Cover/Layers (CC/L)
3
3
7/25/2012
4/17/2013
2013
2013
2014
2014
VIIRS EDR Cloud Effective Particle Size (CEPS)
3
2013
2014
2014
VIIRS EDR Cloud Optical Thickness (COT)
3
2013
2014
2014
VIIRS EDR Cloud Top Height (CTH)
3
2013
2014
2014
VIIRS EDR Land Active Fires
3
10/10/2012
08/2013
2014
VIIRS EDR Sea Ice Characterization
VIIRS EDR Snow Cover - (Fractional Snow Cover + Binary Snow
Cover Mask)
3
5/1/2013
2014
2014
5/1/2013
2014
2014
VIIRS EDR Suspended Matter (SM)
3
2013
2014
2014
VIIRS IP Cloud Mask (VCM) (Delivered IP)
6/27/2012
2/20/2013
2013
VIIRS EDR Aerosol Optical Thickness (AOT)
3
4
9/12/2012
2013
2014
VIIRS EDR Aerosol Particle Size Parameter (APSP)
4
9/12/2012
2013
2014
VIIRS EDR Cloud Base Height
4
2013
2014
2014
VIIRS EDR Cloud Top Pressure
4
2013
2014
2014
VIIRS EDR Cloud Top Temperature
4
2013
2014
2014
VIIRS EDR Ice Surface Temperature
4
5/1/2013
2014
2014
VIIRS EDR Surface Albedo
4
2013
2014
2014
VIIRS EDR Land Surface Temperature (LST)
4
12/19/2012
2013
2013
VIIRS EDR Surface Type (ST)
4
2/27/2013
2014
2014
VIIRS EDR Vegetation Index (VI)
4
2/6/2013
2013
2014
VIIRS IP Quarterly Surface Type (QST) (Delivered IP)
4
2013
2014
2014
VIIRS IP Surface Reflectance
4
2/6/2013
2014
2014
Algorithm Maturity Status
Priority
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p-Date
2/6/2013
v-Date
2013