A new, low-cost sun photometer for student use
Abstract
We have designed a sun photometer for the measurement of aerosol optical thickness (AOT) at 505 nm and 620 nm, using custom-made glass filters (9.5 nm bandpass, FWHM) and photodiodes. The recommended price-point (US150 - US200) allowed us to incorporate technologies such as microcontrollers, a sun target, a USB port for data uploading, nonvolatile memory to contain tables of up to 127 geolocation profiles, extensive calibration data, and a log of up to 2,000 measurements. The instrument is designed to be easy to use, and to provide instant display of AOT estimates. A diffuser in the fore-optics limits the sensitivity to pointing error. We have developed postprocessing software to refine the AOT estimates, format a spreadsheet file, and upload the data to the GLOBE website. We are currently finalizing hardware and firmware, and conducting extensive calibration/validation experiments. These instruments will soon be in production and available to the K-12 education community, including and especially the GLOBE program.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.A51A0160E
- Keywords:
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- 0305 ATMOSPHERIC COMPOSITION AND STRUCTURE / Aerosols and particles;
- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques;
- 3360 ATMOSPHERIC PROCESSES / Remote sensing