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NOAA-18 Instrument Calibration and Validation Briefing . NOAA/NESDIS/Office of Research and Applications As of the Week of June 20, 2005 For archived activities and latest news, please visit http://www.orbit.nesdis.noaa.gov/smcd/spb/n18calval. Weekly Highlights (June 20-24). HIRS
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NOAA-18 Instrument Calibration and Validation Briefing NOAA/NESDIS/Office of Research and Applications As of the Week of June 20, 2005 For archived activities and latest news, please visit http://www.orbit.nesdis.noaa.gov/smcd/spb/n18calval
Weekly Highlights (June 20-24) • HIRS • On June 23, HIRS noise continues dropping. Several channels are now meeting the NEDN noise specification • AMSU-A • AMSU-A2 geolocation and co-registration errors are being confirmed • AMSU scan bias symmetry characterization • AMSU cloud liquid water • AVHRR • SST and aerosol diagnostics • MHS • Scan bias characterization • Possible geolocation errors
NOAA-18 Instrument Payload We focus on these instruments: • AVHRR/4 Advanced Very High Resolution Radiometer • HIRS/4 High Resolution Infrared Sounder • AMSU-A Advanced Microwave Sounding Unit-A • MHS Microwave Humidity Sounder • SBUV/2 Solar Backscattered Ultraviolet Radiometer
Calibration and Validation Legend • PRT: Platinum Resistance Thermometers • NEDN/T: Noise Equivalent Delta Radiance/Temperature • ATOVS: Advanced TIROS Operational Vertical Sounder (TOVS) • TOAST: Total Ozone Analysis using SBUV/2 and TOVS • MSPPS: Microwave Surface and Precipitation Product System • NDVI: Normalized Difference Vegetation Index • SST: Sea Surface Temperature • UV: Ultraviolet • TPW: Total Precipitable Water • CLW: Cloud Liquid Water
ORA NOAA-18 Instrument Cal/Val Mission Goals • Monitor and improve NOAA-18 instrument post-launch calibration • Assess and quantify instrument noises though analyzing calibration target counts and channel measurements • Monitor possible instrument anomaly and provide recommended solution • Quantify satellite geolocation errors • Characterize other biases in radiance and products such as cross-track asymmetry through forward modeling and inter-satellite calibration • Validate NESDIS NOAA-18 products (ATOVS and MSPPS, TOAST, UV index, NDVI, SST) for operational implementation • Provide early demonstration and assessments of NOAA-18 data for improving numerical weather prediction through JCSDA
Mitch Goldberg: ORA/SMCD Division Chief, - Management and Technical Oversight Fuzhong Weng: ORA/SMCD/Sensor Physics Branch Chief and NOAA-18 cal/val team leader, instrument asymmetry and microwave products and algorithms, radiance bias assessments for NWP model applications Changyong Cao: HIRS instrument calibration Fred Wu: AVHRR VIS/IR instrument calibration Tsan Mo: AMSU/MHS instrument calibration Jerry Sullivan: AVHRR thermal channel calibration/ NDVI validation Tony Reale: HIRS/AMSU/MHS sounding channel/products validation Mike Chalfant: HIRS/AMSU/MHS sounding channel/products validation /geolocation Ralph Ferraro: AMSU/MHS window channels/MSPPS products validation Larry Flynn: SBUV product validation Tom Kleespies: AMSU on-orbit verification Hank Drahos: Sounding product validation Dan Tarpley: AVHRR product NDVI monitoring John LeMashall: Impacts assessments of NOAA-18 data for NWP applications Our Team
HIRS Cal/Val News • HIRS noise continues to drop. Ch3, 11, and 12 now meet the NEDN noise spec. for the first time • Channel 1 spaceview is still out of range most of the time • See NEDN trending on http://www.orbit.nesdisnoaa.gov/smcd/spb/multisensor/hirs/nedn
NOAA-18/HIRS Sample Orbit (June 7, 2005) Brightness Temperature for 19 IR channels ch1 ch2 ch3 ch4 ch5 ch6 ch7 ch8 ch9 ch10 ch11 ch12 ch13 ch14 ch15 ch16 ch17 ch18 Chs 1-12 longwave channels do not meet the spec Ch 12 for water vapor
NOAA-18/HIRS Sample Orbit (June 23, 2005)Brightness temperature for all channels ch1 ch2 ch3 ch4 ch5 ch6 ch7 ch8 ch9 ch10 ch11 ch12 ch13 ch14 ch15 ch16 ch17 ch18 Diminishing noises at all channels except ch1
AMSU Cal/Val News • AMSU-A geo-location and co-registration are being investigated by a few ORA scientists • AMSU-A1 and A2 display some misalignment, and A1 appears to be geolocated slight positive alongtrack and slight positive crosstrack • AMSU-A2 appears to be geolocated negative along track and negative crosstrack • Characterization of AMSU-A2 cross-track asymmetry results in a high quality of products • The absolute asymmetry is characterized by the mean difference between simulations and observations at each beam position • The relative asymmetry is characterized by the mean difference between pairwise left-right side brightness temperature
AMSU Cloud Liquid Water vs. AVHHR Ch4 AMSU cloud liquid water is compared with AVHRR image. AMSU cloud algorithm only retrieves liquid water over oceans. It is seen that the higher amount of liquid water is related to strong convection corresponding to cold IR temperature. This is a sanity check for initial assessments of AMSU cloud algorithms
AVHRR Cal/Val News • AVHRR/3 IR data are used to produce global SST analysis. The products are demonstrated without excessive noises but with biases low (-0.35K to N17 and -0.45K to N16) • AVHRR/3 channel 1 and 2 are used to produce aerosol optical depth and estimate the aerosol angstrom. It is shown that channel 1 is biased high by +6.9%, and channel 2 is biased low by -1.4% Aerosol angstrom exponent (related to a ratio of two AODs in AVHRR channel 1 and 2) is a very sensitive indicator of AVHRR calibration.
MHS Cal/Val News • MHS scan bias characterization • Earth scene brightness temperatures binned as function of scan position • MHS scan asymmetry is characterized by the mean brightness temperatures differenced pairwise left – right (ascending: solid line, descending: dashed • Asymmetry from MHS window channels (89 and 157 GHz) ambiguous: ascending and descending portions of orbit have opposite signature, sounding channels show a slight bias (few tenth degree) with the right side being warmer • MHS geolocation error • The need for a possible - 0.5 degree roll correction
MHS Geolocation Errors The composite images on the right quadrants view the channel difference data from ascending and descending nodes, showing only the main land / sea features which only shows support for a possible small roll correction in the ascending pass