On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments
Two calibration/validation efforts planned for current and future spaceborne microwave sounding instruments will be presented. First, the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) airborne sensor is used to directly validate the microwave radiometers (AMSU and MHS) on several operational sa...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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Society of Photo-optical Instrumentation Engineers
2010
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| Online Access: | http://hdl.handle.net/1721.1/52596 |
| _version_ | 1811072644961796096 |
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| author | Blackwell, William J. Bickmeier, Laura J. Jairam, Laura G. Leslie, R. Vincent |
| author2 | Lincoln Laboratory |
| author_facet | Lincoln Laboratory Blackwell, William J. Bickmeier, Laura J. Jairam, Laura G. Leslie, R. Vincent |
| author_sort | Blackwell, William J. |
| collection | MIT |
| description | Two calibration/validation efforts planned for current and future spaceborne microwave sounding instruments will be presented. First, the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) airborne sensor is used to directly validate the microwave radiometers (AMSU and MHS) on several operational satellites. Comparison results for underflights of the Aqua, NOAA, and MetOp-A satellites will be shown. Second, a potential approach will be presented for on-orbit field-of-view (FOV) calibration of the Advanced Technology Microwave Sounder (ATMS). A variety of proposed spacecraft maneuvers that could facilitate the characterization of the radiometric boresight of all 22 ATMS channels will be discussed. Radiance observations from the NAST-M airborne sensor can be used to directly validate the radiometric performance of spaceborne sensors. NAST-M includes a total of four spectrometers, with three operating near the oxygen lines at 50-57, 118.75, and 424.76 GHz, and a fourth spectrometer centered on the water vapor absorption line at 183.31 GHz. All four feedhorns are co-located, have 3-dB (full-width at half-maximum) beamwidths of 7.5° (translating to 2.5-km nominal pixel diameter at nadir incidence), and are directed at a single mirror that scans cross-track beneath the aircraft with a nominal swath width of 100 km. We will present results for two recent validation efforts: 1) the Pacific THORpex (THe Observing-system Research and predictability experiment) Observing System Test (PTOST 2003, Honolulu, HI) and 2) the Joint Airborne IASI Validation Experiment (JAIVEx 2007, Houston, TX). Radiance differences between the NAST-M sensor and the Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sensor (MHS) were found to be less than 1K for most channels. Comparison results for ocean underflights of the Aqua, NOAA, and MetOp-A satellites are shown. We also present an approach for on-orbit FOV calibration of the ATMS satellite instrument using vicarious calibration sources with high spatial frequency content (the Earths limb, for example). The antenna beam is slowly swept across the target of interest and a constrained deconvolution approach is used to recover antenna pattern anomalies. Various proposed spacecraft maneuvers will be considered, with the intent to illustrate how each maneuver will help to identify and characterize possible FOV artifacts. Radiative transfer simulations that quantitatively assess the benefit of each satellite maneuver will also be presented. |
| first_indexed | 2024-09-23T09:09:18Z |
| format | Article |
| id | mit-1721.1/52596 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:09:18Z |
| publishDate | 2010 |
| publisher | Society of Photo-optical Instrumentation Engineers |
| record_format | dspace |
| spelling | mit-1721.1/525962022-09-30T13:50:32Z On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments Blackwell, William J. Bickmeier, Laura J. Jairam, Laura G. Leslie, R. Vincent Lincoln Laboratory Blackwell, William J. Blackwell, William J. Bickmeier, Laura J. Jairam, Laura G. Leslie, R. Vincent Two calibration/validation efforts planned for current and future spaceborne microwave sounding instruments will be presented. First, the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) airborne sensor is used to directly validate the microwave radiometers (AMSU and MHS) on several operational satellites. Comparison results for underflights of the Aqua, NOAA, and MetOp-A satellites will be shown. Second, a potential approach will be presented for on-orbit field-of-view (FOV) calibration of the Advanced Technology Microwave Sounder (ATMS). A variety of proposed spacecraft maneuvers that could facilitate the characterization of the radiometric boresight of all 22 ATMS channels will be discussed. Radiance observations from the NAST-M airborne sensor can be used to directly validate the radiometric performance of spaceborne sensors. NAST-M includes a total of four spectrometers, with three operating near the oxygen lines at 50-57, 118.75, and 424.76 GHz, and a fourth spectrometer centered on the water vapor absorption line at 183.31 GHz. All four feedhorns are co-located, have 3-dB (full-width at half-maximum) beamwidths of 7.5° (translating to 2.5-km nominal pixel diameter at nadir incidence), and are directed at a single mirror that scans cross-track beneath the aircraft with a nominal swath width of 100 km. We will present results for two recent validation efforts: 1) the Pacific THORpex (THe Observing-system Research and predictability experiment) Observing System Test (PTOST 2003, Honolulu, HI) and 2) the Joint Airborne IASI Validation Experiment (JAIVEx 2007, Houston, TX). Radiance differences between the NAST-M sensor and the Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sensor (MHS) were found to be less than 1K for most channels. Comparison results for ocean underflights of the Aqua, NOAA, and MetOp-A satellites are shown. We also present an approach for on-orbit FOV calibration of the ATMS satellite instrument using vicarious calibration sources with high spatial frequency content (the Earths limb, for example). The antenna beam is slowly swept across the target of interest and a constrained deconvolution approach is used to recover antenna pattern anomalies. Various proposed spacecraft maneuvers will be considered, with the intent to illustrate how each maneuver will help to identify and characterize possible FOV artifacts. Radiative transfer simulations that quantitatively assess the benefit of each satellite maneuver will also be presented. National Oceanic and Atmospheric Administration (Air Force contract FA8721-05-C-0002) 2010-03-15T19:48:16Z 2010-03-15T19:48:16Z 2008-12 2008-11 Article http://purl.org/eprint/type/JournalArticle 0277-786X SPIE CID: 71540A-12 http://hdl.handle.net/1721.1/52596 Blackwell, William J. et al. “On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments.” Microwave Remote Sensing of the Atmosphere and Environment VI. Noumea, New Caledonia: SPIE, 2008. 71540A-12. © 2008 SPIE en_US http://dx.doi.org/10.1117/12.804948 Proceedings of SPIE--the International Society for Optical Engineering Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Society of Photo-optical Instrumentation Engineers SPIE |
| spellingShingle | Blackwell, William J. Bickmeier, Laura J. Jairam, Laura G. Leslie, R. Vincent On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments |
| title | On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments |
| title_full | On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments |
| title_fullStr | On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments |
| title_full_unstemmed | On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments |
| title_short | On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments |
| title_sort | on orbit radiometric validation and field of view calibration of spaceborne microwave sounding instruments |
| url | http://hdl.handle.net/1721.1/52596 |
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