Characterization of fine resolution field spectrometers using solar Fraunhofer lines and atmospheric absorption features

Fraunhofer Lines (Origin in the Solar Atmosphere) and Atmospheric Absorption Features (Origin in the Earth’s Atmosphere) Exploited in this Study ^a

^a  Window progressive number, elements causing the features, origin (solar or terrestrial), wavelengths of irradiance minimum (numbers in bold italic refer to the shortest and longest wavelengths of the range influenced by absorption), width of the features (FWHM), and spectral range of the window considered in the optimization procedure.
^b  WV stands for water vapor.

Characteristics of the Spectrometers Used (OceanOptics, USA, and Analytical Spectral Devices Inc., USA) ^a

^a  Note that actual ASD wavebands (1.4 and $1.6\mathrm{nm}$ SSI) are not reported in saved spectra but undergo an automatic linear interpolation to a $1\mathrm{nm}$ SSI.

Spectral Shift and FWHM Retrieved by the Algorithm Application with Cost Functions ${\mathsf{C}}_{\mathsf{r}}$ and ${\mathsf{C}}_{\mathsf{\text{ratio}}}$ and by Laboratory Calibration at the Various Spectral Windows ^a

^a  Bias and RMSE are computed between laboratory values and algorithm estimates. As concerns the analysis of SS accuracy, the central wavelength of the spectral window considered in the optimization is reported. Columns ${C_r}^{*}$ and ${C_{\text{ratio}}}^{*}$ show the algorithm estimates of FWHM at the argon–mercury lamp emission wavelengths. These values were computed as the linear interpolation of the algorithm estimates at the two closest windows.

Table 1

Fraunhofer Lines (Origin in the Solar Atmosphere) and Atmospheric Absorption Features (Origin in the Earth’s Atmosphere) Exploited in this Study ^a

^a  Window progressive number, elements causing the features, origin (solar or terrestrial), wavelengths of irradiance minimum (numbers in bold italic refer to the shortest and longest wavelengths of the range influenced by absorption), width of the features (FWHM), and spectral range of the window considered in the optimization procedure.
^b  WV stands for water vapor.

Table 2

Characteristics of the Spectrometers Used (OceanOptics, USA, and Analytical Spectral Devices Inc., USA) ^a

^a  Note that actual ASD wavebands (1.4 and $1.6\mathrm{nm}$ SSI) are not reported in saved spectra but undergo an automatic linear interpolation to a $1\mathrm{nm}$ SSI.

Table 3

Spectral Shift and FWHM Retrieved by the Algorithm Application with Cost Functions ${\mathsf{C}}_{\mathsf{r}}$ and ${\mathsf{C}}_{\mathsf{\text{ratio}}}$ and by Laboratory Calibration at the Various Spectral Windows ^a

^a  Bias and RMSE are computed between laboratory values and algorithm estimates. As concerns the analysis of SS accuracy, the central wavelength of the spectral window considered in the optimization is reported. Columns ${C_r}^{*}$ and ${C_{\text{ratio}}}^{*}$ show the algorithm estimates of FWHM at the argon–mercury lamp emission wavelengths. These values were computed as the linear interpolation of the algorithm estimates at the two closest windows.