Instrument Characteristics:

These plots define the normalized ratio or error of the measured angular response to ideal(cosine) response for each channel for each shadowband instrument. This radiometric characterization is made along two orthogonal planes (-90 to +90 south-north and -90 to +90 west-east) of the diffuser. The UV-MFRSR foreoptic is designed for near-perfect angular response, and the Lambertian response of these instruments has been described by Harrison et al. (1994) and Michalsky et al. (1995). These angular corrections are applied to the direct-beam measurement, and also to the diffuse measurement assuming isotropic sky irradiance, then these corrected direct and diffuse values are added to get a revised total horizontal value.

These plots define the measured full width at half maximum (FWHM) bandwidth and center wavelength (centroid), as determined with a precision narrowband spectrometer. This spectral response characterization is used to monitor the stability of the UV-MFRSR instruments, as described by Bigelow et al. (2000).

These plots display the Langley voltage intercepts collected for each channel, for the instrument and board settings in use at the site on the requested date. The Langley method is described in Harrison and Michalsky (1994). Voltage intercepts represent the voltage that would be measured by the detector at the top of the atmosphere. Points falling more than two standard deviations from the regression line were omitted.

This listing provides a history of calibration co-efficients for an instrument selected by serial number. Responsivities are listed for the instrument for all deployments for each filter channel.