Research Article

Space Weather impact on the degradation of NOAA POES MEPED proton detectors

Birkeland Centre for Space Science (BCSS), Department of Physics and Technology, University of Bergen, Allégaten 55, N-5007 Bergen, Norway

^* Corresponding author: linn-kristine.odegaard@uib.no

Received: 20 December 2015
Accepted: 12 May 2016

Abstract

The Medium Energy Proton and Electron Detector (MEPED) on board the National Oceanic and Atmospheric Administration Polar Orbiting Environmental Satellites (NOAA POES) is known to degrade with time. In recent years a lot of effort has been put into calibrating the degraded proton detectors. We make use of previous work and show that the degradation of the detectors can be attributed to the radiation dose of each individual instrument. However, the effectiveness of the radiation in degrading the detector is modulated when it is weighted by the mean ap index, increasing the degradation rate in periods with high geomagnetic activity, and decreasing it through periods of low activity. When taking ap and the radiation dose into account, we find that the degradation rate is independent of spacecraft and detector pointing direction. We have developed a model to estimate the correction factor for all the MEPED detectors as a function of accumulated corrected flux and the ap index. We apply the routine to NOAA POES spacecraft starting with NOAA-15, including the European satellites MetOp-02 and MetOp-01, and estimate correction factors.