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Effects of switch leakages upon nimbus-7 smmr calibration
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Kim, Seung T. Han, Daesoo |
| Copyright Year | 1988 |
| Description | A calibration model for the Nimbus 7 Scanning Multichannel Microwave Radiometer (SMMR) is studied. This model not only removes major drawbacks of the current calibration model but also helps in the understanding of the performance degradation of the aging instrument. The current Nimbus 7 SMMR calibration algorithm was derived without considering the interference effect between the two orthogonally polarized signals merging at a ferrite polarization selector switch. The resulting calibrated brightness temperatures, considered as a function of scan angle, are not symmetric around scan angle = 0. However, neither the origin of the asymmetry nor the manner in which the two orthogonal components are mixed has been fully understood. The new calibration model proposed incorporates all the leakage factors associated with the ferrite switches along the signal paths. The resulting calibration equations clarify how the orthogonal components of surface brightness are coupled at radiometers. As a consequence, the origin of the asymmetry is clearly identified and explained. In addition, the feasibility of absolute calibration using in-orbit data is discussed. |
| File Size | 715107 |
| Page Count | 26 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19910007223 |
| Archival Resource Key | ark:/13960/t6zw6br68 |
| Language | English |
| Publisher Date | 1988-06-01 |
| Access Restriction | Open |
| Subject Keyword | Oceanography Leakage Polarization Characteristics Calibrating Scanners Electric Switches Microwave Radiometers Ferrites Algorithms Asymmetry Electromagnetic Interference Nimbus 7 Satellite Mathematical Models Brightness Temperature Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
