Cross-Calibration of Far UV Spectra of Solar System Objects and the Heliosphere (ISSI Scientific Report Series Book 13)

This book is the result of a working group sponsored by ISSI in Bern, which was initially created to study possible ways to calibrate a Far Ultraviolet (FUV) instrument after launch. In most cases, ultraviolet instruments are well calibrated on the ground, but unfortunately, optics and detectors in the FUV are very sensitive to contaminants and it is very challenging to prevent contamination before and during the test and launch sequences of a space mission. Therefore, ground calibrations need to be confirmed after launch and it is necessary to keep track of the temporal evolution of the sensitivity of the instrument during the mission. The studies presented here cover various fields of FUV spectroscopy, including a catalog of stellar spectra, datasets of Moon Irradiance, observations of comets and measurements of the interplanetary background. Detailed modelling of the interplanetary background is presented as well. This work also includes comparisons of older datasets with current ones. This raises the question of the consistency of the existing datasets. Previous experiments have been calibrated independently and comparison of the datasets may lead to inconsistencies. The authors have tried to check that possibility in the datasets and when relevant suggest a correction factor for the corresponding data. This book is the result of a working group sponsored by ISSI in Bern, which was initially created to study possible ways to calibrate a Far Ultraviolet (FUV) instrument after launch. In most cases, ultraviolet instruments are well calibrated on the ground, but unfortunately, optics and detectors in the FUV are very sensitive to contaminants and it is very challenging to prevent contamination before and during the test and launch sequences of a space mission. Therefore, ground calibrations need to be confirmed after launch and it is necessary to keep track of the temporal evolution of the sensitivity of the instrument during the mission. The studies presented here cover various fields of FUV spectroscopy with the exclusion of direct solar UV spectroscopy, including a catalog of stellar spectra, data-sets of lunar Irradiance, observations of comets and measurements of the interplanetary background. Detailed modeling of the interplanetary background is presented as well. This work also includes comparisons of older data-sets with current ones. This raises the question of the consistency of the existing data-sets. Previous experiments have been calibrated independently and comparison of the data-sets may lead to inconsistencies. The authors have tried to check that possibility in the data-sets and when relevant, suggest a correction factor for the corresponding data. Front Matter....Pages i-vii Introduction....Pages 1-3 Front Matter....Pages 5-5 Distribution of Interstellar Hydrogen Atoms in the Heliosphere and Backscattered Solar Lyman-α....Pages 7-65 Solar Parameters for Modeling the Interplanetary Background....Pages 67-138 Front Matter....Pages 139-139 Thirty Years of Interplanetary Background Data: A Global View....Pages 141-162 Lyman- α Models for LRO LAMP from MESSENGER MASCS and SOHO SWAN Data....Pages 163-175 New Horizons Cruise Observations of Lyman- α Emissions from the Interplanetary Medium....Pages 177-188 Front Matter....Pages 189-189 A New Catalog of Ultraviolet Stellar Spectra for Calibration....Pages 191-226 Absolute Ultraviolet Irradiance of the Moon from the LASP Lunar Albedo Measurement and Analysis from SOLSTICE (LLAMAS) Project....Pages 227-253 Lyman-α Observations of Comet Holmes from SORCE SOLSTICE and SOHO SWAN....Pages 255-267 Back Matter....Pages 269-275