Dr. Vaibhav Gupta

Designed and built at USC’s Space Sciences Center (SSC), the Solar EUV Monitor (SEM) on NASA/ESA Solar Heliospheric Observatory (SOHO,1996) and its successor Extreme Ultraviolet Spectrophotometer (EVE/ESP) on NASA Solar Dynamics Observatory (SDO, 2010), provided long-term in orbit EUV solar irradiance measurements for studying solar spectral variability, flare dynamics and model impacts on space weather. However, significant degradation over time of thin-film aluminum EUV bandpass filters was observed on both SOHO/SEM and SDO/ESP in space, causing drastic reduction of their (EUV) transmission, requiring periodic calibrations with sounding rocket under-flights. I will present here our collective experiences (at SSC) of instrument operations/calibrations, contamination studies, and development of improved EUV bandpass flight filters with protective monolayers. Exposure to ionizing radiation from galactic cosmic rays and solar energetic particles at aircraft flight altitudes and above can have an adverse effect on human health. In the second half, I will talk about Automated Radiation Measurements for Aerospace Safety (ARMAS) for aviation. ARMAS dosimeters subsequently provided simultaneous measurements of radiation at the top and bottom of the atmosphere using six different platforms at varying altitudes, at the same latitude and longitude columns. This enabled one of the first such studies, that captured dose throughout a full 3D column from space to the ground, comparing measurements to models (NAIRAS) of the radiation environment between International Space Station and commercial aviation altitudes.