Calibration and Metrological Characteristics of Equipment for Satellite Monitoring of Geoeffective Solar Ultraviolet Radiation

The results are considered of calibration of semiconductor detectors of the VUSS-E spectrophotometer intended for monitoring the solar ultraviolet radiation flux in the Lyman-alpha line (L , 121.6 nm) on Roshydromet geostationary satellites. The calibration was carried out at the Kosmos metrological station at the Siberian International Center for Synchrotron Radiation in the channel of the VEPP-4 relativistic electron storage ring. The contribution to the VUSS-E signal from the L line and from the spectral region above 122 nm is calculated using the model ultraviolet radiation spectra. It is shown that the value of can vary greatly for different sensors and different levels of solar activity: % at a low level and % at a high level of solar activity. This result indicates a need to calibrate all channels of each flight instrument and to take into account the dependence of the contribution to the VUSS-E signal from the L line on the level of solar activity when monitoring space weather.