Radiance and irradiance are the two fundamental quantities in remote sensing applications. The Spectral Measurements for Atmospheric Radiative Transfer (SMART) unit includes broadband solar/terrestrial radiometers (SMART-r for irradiance) and ultraviolet-visible-infrared spectroradiometer (SMART-s for radiance). The SMART-r units are calibrated using the NIST-traceable lamp considering thermal-dome-effect (TDE), which provide surface solar irradiance of about 1% accuracy. The SMART-s units, originally developed by the Pandora network group, cover broader spectral range from 280 to 820 nm, which includes ozone Chappuis band. The SMART-s units are calibrated in laboratory using a variety of narrow-line and broadband emission lamps, and in the field using sun/sky radiances. The spectral measurements of SMART-s also provide valuable information on atmospheric trace gases and aerosols. In this presentation, I will briefly show the calibration procedures of SMART units. Then, I will present the simultaneous retrieval algorithm of trace gases and aerosols for the SMART-s, as well as its validation/comparison results. I will also summarize theoretically estimated information contents and retrieval accuracy of the SMART-s products. Finally, I will show past and current activities/roles of the SMART units for various field campaigns including the High Mountain Asia project in Nepal.
Seminar Series Coordinators