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Recent Field Campaigns with CERES Instruments

Recent Field Campaigns with CERES Instruments. Z. Peter Szewczyk Kory J. Priestley Lou Smith. Remote Sensing of Clouds and the Atmosphere XI, Stockholm, 09/11-14, 2006. Presentation Outline. CERES mode for special observations Planning tools under new restrictive rules

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Recent Field Campaigns with CERES Instruments

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  1. Recent Field Campaigns with CERES Instruments Z. Peter Szewczyk Kory J. Priestley Lou Smith Remote Sensing of Clouds and the Atmosphere XI, Stockholm, 09/11-14, 2006 Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  2. Presentation Outline • CERES mode for special observations • Planning tools under new restrictive rules • Field campaigns of 2006 • FM1/FM3 comparison • FM2/GERB1 comparison • AMMA support • SCALES support • True AT • Summary Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  3. CERES Clouds and the Earth’s Radiant Energy System Instrument • Narrow field-of-view (15x30km at nadir) scanning radiometer: • Shortwave channel (0.3-5mm), • Total channel (0.3-100mm), • Window channel (8-12mm) • PFM on board TRMM (1998, failed 06/2000) • FM1 & FM2 on board Terra (in service from 03/2000) • FM3 & FM4 on board Aqua (from 06/2002, SW of FM4 is out ) Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  4. Terra & Aqua orbits Aqua Terra • Sun-synchronous, inclination angle 98.2o and 81.8o • Equator crossing time: 10:30AM Terra and 1:30PM Aqua • about 15 minutes apart at nodes Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  5. CERES normal operation modes • Cross-track (XT) Scan • Rotational Azimuth Plane Scan (RAPS) • Constant RAZ rate • Ram direction restrictions • Suspended due to degradation investigation Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  6. Scan mode for special operations • In Programmable Azimuth Plane Scan (PAPS) mode, scanning plane orientation follows a prescribed schedule • Step-wise changes of the azimuth angle • Time and angle changes depend on satellite position in an orbit • New elevation profile due to ram direction restrictions • Increases sampling by orders of magnitude Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  7. CERES special operation tools • Objectives of special observations using PAPS: • Earth targets • Matching viewing geometry of other instruments • Sampling within required scan plane orientation • Relative azimuth (RAZ) predictions (web-based) • Obtain 7-day satellite ground track file from Goddard • Compute scanner orientation for each scan (every 6.6s) • Generate daily RAZ prediction files for commanding • Automated Command uploads • One-day sequences (ODS) formatted for a direct upload Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  8. Field campaigns of 2006 Summer of 2006: • Terra-Aqua (FM1/FM3) comparison in June • CERES-GERB (FM2/GERB1) comparison in June • African Monsoon Multidisciplinary Analysis (AMMA) in July • Ground validation for GERB2 and GERB1 at Valencia Anchor Station (VAS) early August • True along-track (AT) scan every other Tuesday starting on 08/22 Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  9. Terra-Aqua comparison • CERES radiances belong to two-decade long Earth’s radiation budget dataset • Greenland is the most homogenous: • FM1 and FM3 15 minutes apart • Scans orthogonal to the solar plane • Using short nadir scan profile to avoid ram directions • Validation campaign: • 06/05 – 06/30, 2006 • 600 orbital crossings of about 90 seconds each • Significant amount of data for statistical analysis Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  10. FM1/FM3 scanning pattern 15:04 (GMT) on 06/05/2006 15:19 (GMT) on 06/05/2006 Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  11. FM1 daily scanning Filtered shortwave radiances on 06/05/2006 0 100 217 Watts per square meter per steradian Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  12. FM2/GERB1 comparison • GERB radiances part of the ERB dataset • Campaign around the summer solstice of 2006 • CERES matches GERB viewing geometry (located at 6.5W) • FM2 on Terra in the PAPS mode for 25 days • 4 daytime orbits per day for about 45 min scanning • Ram restrictions result in the Northern Hemisphere data only • The use of the short nadir scan profile doubles matched footprints Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  13. GERB measurements • Geo-stationary Earth Radiation Budget instrument • On board Meteosat-9 located at 6.5W in June • Array of 256 detectors covering the visible portion of the Earth • Short and long-wave radiation image every 15min. Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  14. FM2-GERB1 Pass at 9:44 (GMT) on 06/18/2006 Pass at 11:21 (GMT) on 06/18/2006 Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  15. GERB ground validation • To validate GERB radiances with ground data • Geo Earth Radiation Budget instrument with 256 detectors • Valencia Anchor Station (VAS): 39.34oN and 1.17oW • Of GERB pixel size (50x50 km) and quite homogenous • Ground instrumentation by University of Valencia • CERES measurements on July 31- August 6, 2006: • FM2 on Terra – one or two passes per day • about 2.5 minutes of data Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  16. FM2 daily scanning over VAS Pass at 11:47 (GMT) on 08/01/2006 Pass at 10:09 (GMT) on 08/01/2006 Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  17. African Monsoon Multidisciplinary Analysis (AMMA) • To understand the impact of monsoons • Niamey/Niger site: 13.47oN and 2.17oE • Focus on clouds dynamics, air pollution • CERES measurements in July (10th on) of 2006: • FM2 on Terra • One orbit per day for about 2.5 minutes Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  18. FM2 over Niamey (AMMA) Command sequence at 10:51 (GMT) on 07/26/2006 Targeting the site Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  19. True along-track scan • To eliminate a spatial mismatch between nadir and oblique observations • Original implementation: • RAZ fixed, along the satellite velocity vector • Earth’s rotation causes a wide swath of footprints • New implementation: • RAZ changes to account for the Earth’s rotation • Significantly reduced spread of footprints Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  20. Footprints spread swath shown on a 5º by 10º grid • RAZ corrections: ±4º • about 80km mismatch between nadir and oblique (55º VZA) observations reduced to 3km Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  21. 2006 campaign summary Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

  22. Concluding remarks • Busy summer of 2006 for CERES • Programmable Azimuth mode used for meeting data collection goals • Planning tools reside on the website • Despite ram restrictions, large amount of data was collected • Free service to the science community http://asd-www.larc.nasa.gov/PAPS/cgi-bin/rygar.cgi Z. P. Szewczyk GIST 25, 23-25 Oct. 2006

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