Phase Sensitive Detection for the SORCE Total Irradiance Monitor
Abstract
The Total Irradiance Monitor (TIM) on the SOlar Radiation and Climate Experiment (SORCE) will measure the total solar irradiance (TSI). The TIM will report four TSI measurements daily, continuing the current 24-year record of solar irradiance through SORCE's goal 5-year mission life. This instrument was designed to achieve a relative standard uncertainty (1 σ precision) of 100 parts per million (ppm) and a precision and long-term uncertainty of 10 ppm/year. The major innovation the TIM brings to spaceborne TSI measurements is phase sensitive detection. This new instrument was designed from the ground up with the primary consideration being low-noise performance at the shutter fundamental, minimizing parasitic effects at and in-phase with the instrument's shutter. The DSP-controlled thermal balance and this phase sensitive detection method reduce sensitivity to thermal fluctuations and noise, enabling the instrument's high precision. We describe in detail here the phase sensitive detection algorithm used for the TIM.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AGUFMSH52A0496K
- Keywords:
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- 1650 Solar variability;
- 1694 Instruments and techniques;
- 7536 Solar activity cycle (2162);
- 7537 Solar and stellar variability;
- 7594 Instruments and techniques