NOAA-18 Instrument Calibration and Validation Briefing

1. NOAA-18 Instrument Calibration and Validation Briefing NOAA/NESDIS/Office of Research and Applications As of the Week of July 11, 2005 For archived activities and latest news, please visit http://www.orbit.nesdis.noaa.gov/smcd/spb/n18calval

2. Weekly Highlights (July 11-15) • HIRS Cal/Val • HIRS noise remains fluctuating and most LW channels do not meet the noise specification • Bias characterization for several HIRS LW channels • NESDIS ATOVS Plan • Demonstrate IOC using combined NOAA-18 HIRS, AMSU-A and MHS in operational sounding products generation • Demonstrate impacts of reduced FOV size for HIRS onboard NOAA-18 from 17km to 10km • The Metoffice Assessments on Direct Broadcast NOAA-18 Data • Quantify the errors through comparing direct broadcast data with NOAA global level-1b

3. NOAA-18 Instrument Payload We focus on these instruments: • AVHRR/3 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

4. 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

5. 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

6. 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

7. HIRS Cal/Val Summary • The filterwheel was put in high power mode for one orbit on July 12. So far, there is no impact from this test on the HIRS LW noise level • HIRS channel 1 through 4, and channel 12 are not (yet) suitable for product generation • NOAA-18 HIRS channel 5 displays a cold bias on the order of 5 K • NOAA-16 and 18 HIRS channel 8 are comparable

8. HIRS Channel 5 calibrated radiance temperatures (K) are compared for N15 (upper left), N16 (upper right) and NOAA-18; each panel is scaled identically allowing direct color comparison of differences. The region of coverage is an approximately 5000 km2 region in the remote west tropical pacific. Random noise characteristics for N18 are now comparable to N16; a cool bias (less red) on the order of 5K is observed for N18 measurements relative to N16.

9. HIRS Channel 8 calibratedradiance temperatures (K) are compared for N15 (upper left), N16 (upper right) and NOAA-18; each panel is scaled identically allowing direct color comparison of differences. The region of coverage is an approximately 5000 km2 region in the remote west tropical pacific. Random noise characteristics for N18 are now comparable to N16 for this channel; HIRS channel 8 is a critical channel for cloud detection.

10. HIRS Channel 12 calibrated radiance temperatures (K) are compared for N15 (upper left), N16 (upper right) and NOAA-18; each panel is scaled identically allowing direct color comparison of differences. The region of coverage is an approximately 5000 km2 region in the remote west tropical pacific. Random noise characteristics for N18 are now comparable to N16 but still unsuitable for products generation.

11. Plan for ATOVS-200x • Demonstrate IOC using combined NOAA-18 HIRS, AMSU-A and MHS in operational sounding products generation: • Develop contingencies for removing selected HIRS channels (i.e., channels 1, 2, 3, 4, and 12) • Deploy revised ATOVS-200X scientific algorithms to realize maximum impact from available data • Demonstrate impacts of reduced FOV size for HIRS onboard NOAA-18 from 17km to 10km: • Cloud detection • Sounding products • Cloud products

12. AMSU channel 16 brightness temperature difference – differences only arise from mapping differences e.g. near coastlines not from calibration of data which agrees to within 0.1 The Metoffice Assessments using Direct Broadcast NOAA-18 Data • Local global consistency is at least as good as NOAA-16 and in some respects better due to AAPP processing aligning more closely with NOAA processing. • The direct broadcast facility is working very well and direct broadcast AMSU-A and MHS data can be used with confidence in data assimilation systems or for product generation (given that other studies have confirmed quality of the global data). • As with NOAA-16 the match for HIRS is not as good as for microwave channels but unlike NOAA-16 several HIRS channels are now agreeing very well and consideration could be given to using some HIRS channels from direct broadcast data. There is an problem for HIRS channel 1 which is not yet understood and is under investigation in the AAPP team.