Cross-Calibration of the GPS Constellation CXD Proton Data with GOES EPS

Journal Article · 20 February 2018 · Space Weather

DOI: https://doi.org/10.1002/2017SW001750 · OSTI ID:1423980

Carver, Matthew Robert  ^[1]; Sullivan, John P.  ^[1]; Morley, Steven Karl  ^[1]; Rodriguez, Juan V. ^[2]

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1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. National Oceanic and Atmospheric Administration (NOAA), Boulder, CO (United States); Univ. of Colorado, Boulder, CO (United States)

Accurate proton flux measurements of the near Earth environment are essential to the understanding of many phenomena which have a direct impact on our lives. Currently there is only a small set of satellites capable of performing these measurements which makes certain studies and analyses difficult. This paper details the capabilities of the Combined X-ray Dosimeter (CXD), flown on 21 satellites of the Global Positioning System (GPS) constellation, as it relates to proton measurements. We present a cross-calibration of the CXD with the Energetic Particle Sensor (EPS) onboard the Geostationary Operational Environmental Satellite (GOES) operated by the National Oceanic and Atmospheric Administration (NOAA). By utilizing Solar Energetic Particle Events (SEPEs) when both sets of satellites were operational we have orders of magnitude in flux and energy to compare against. Robust statistical analyses show that the CXD and GOES flux calculations are similar and that for proton energies > 30 MeV the CXD fluxes are on average within 20% of EPS. Although the CXD has a response to protons as low as 6 MeV the sensitivity at energies below 20 MeV is reduced and so flux comparisons of these are generally worse. Integral flux values > 10 MeV are typically within 40% of EPS. These calibrated CXD data sets will give researchers capabilities to study solar proton access to the inner magnetosphere down to L ~ 4 near the equatorial plane at high temporal cadence.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1423980
• Report Number(s): LA-UR-17-30489
• Journal Information: Space Weather, Vol. 16, Issue 3; ISSN 1542-7390
• Publisher: American Geophysical UnionCopyright Statement
• Country of Publication: United States
• Language: English