Abstract
We present a new solar irradiance reference spectrum representative of
solar minimum conditions between solar cycles 24 and 25. The Total and
Spectral Solar Irradiance Sensor-1 (TSIS-1) Hybrid Solar Reference
Spectrum (HSRS) is developed by applying a modified spectral ratio
method to normalize very high spectral resolution solar line data to the
absolute irradiance scale of the TSIS-1 Spectral Irradiance Monitor
(SIM) and the CubeSat Compact SIM (CSIM). The high spectral resolution
solar line data are the Air Force Geophysical Laboratory ultraviolet
solar irradiance balloon observations, the ground-based Quality
Assurance of Spectral Ultraviolet Measurements In Europe Fourier
transform spectrometer solar irradiance observations, the Kitt Peak
National Observatory solar transmittance atlas, and the semi-empirical
Solar Pseudo-Transmittance Spectrum atlas. The TSIS-1 HSRS spans 202 nm
to 2730 nm at 0.01 to ~0.001 nm spectral resolution with
uncertainties of 0.3% between 460 and 2365 nm and 1.3% at wavelengths
outside that range.