Investigation of Space Radiation-Induced Effects on the Performance of CCD Detectors Using Radiation Monitor’s In-Flight Measurements

Abstract

Performance stability of optical imaging systems during mission lifetime is a central issue for space optical Earth observation (EO) missions due to the harsh conditions in low-Earth-orbit (LEO) environments. Although they are adequately designed and protected to operate in the space environment, charge-coupled device (CCD) detectors, in particular, are subject, during their in-orbit lifetime, to many damaging effects caused by space radiation. These damages may result in the degradation of several CCD performance characteristics threatening consequently optical imaging systems’ performance and durability. Experience feedback from in-space measurements becomes very useful in identifying any degradation and measuring its effects on CCD detectors’ performance. This allows for a better understanding of what happens during a mission and enables comparisons between the in-orbit behavior and results of on-ground predictions and tests that cannot be performed under faithfully reproduced space mission conditions. The present work aims to assess the space radiation-induced impacts on CCD detectors’ performance parameters by making use of in-flight environment data and measurements made by the radiation monitor embarked onboard an EO microsatellite. The main contribution of this work is the link of the occurrence of the radiation-induced damage effects in CCD detectors with the in-orbit nature and amount of radiation the spacecraft was exposed to. The findings of this analysis are of primary importance for future space optical EO missions, as they provide a valuable experimental heritage to optimize design strategies and develop dedicated mitigation measures to ensure the proper operation of imaging instruments.