High precision refraction measurements by solar imaging during occultation: results from SOFIE
Larry Gordley1, John Burton, Benjamin T Marshall
1GATS, Incorporated, 11864 Canon Boulevard, Suite 101, Newport News, Virginia 23606, USA. l.l.gordley@gats-inc.com
Applied Optics
|September 3, 2009
Summary
A novel method precisely measures atmospheric refraction angles using simultaneous solar edge observations. This technique enables accurate temperature profiling of the lower mesosphere.
Area of Science:
- Atmospheric science
- Geophysics
- Optical remote sensing
Background:
- Accurate measurement of atmospheric refraction is crucial for remote sensing and understanding atmospheric dynamics.
- Existing methods face limitations in precision and error correction, particularly concerning instrument attitude uncertainty.
Purpose of the Study:
- To introduce and validate a new, highly precise method for measuring atmospheric refraction angles.
- To demonstrate the method's capability for temperature sounding in the lower mesosphere.
Main Methods:
- Utilizes simultaneous observation of the top and bottom edges of the solar image during occultation to eliminate attitude errors.
- Employs a normalized difference measurement for refraction angles, minimizing absolute error.
- Applies edge location fitting using a large number of detector pixels and a known edge shape.
Main Results:
- Achieved in-orbit measurement precision of +/-0.02 arcsec (+/-0.1 microrad) for atmospheric refraction angles.
- The method effectively mitigates errors from instrument attitude uncertainty.
- Demonstrated the potential for temperature sounding up to the lower mesosphere.
Conclusions:
- The presented method offers a significant advancement in measuring atmospheric refraction angles with unprecedented precision.
- This technique provides a reliable tool for atmospheric remote sensing and temperature profiling.
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