Johnson, Adam Alan (2010-08). Space Weather Effects on Imaging Detectors in Low Earth Orbit. Master's Thesis. Thesis uri icon

abstract

  • The objective of this research is the statistical study of space weather e ects on im- age detectors in Low Earth Orbit. The Hubble Space Telescope is used as a resource for acquiring proton a ected images for statistical analysis. For the purpose of the present work, the space weather environment will consist of cosmic as well as solar proton particles. The proton occurrences evident in images from the Hubble Charge Coupled Device (CCD) have been used to calculate the probability of proton events, which is related to the local space weather particle ux. The proton particles transfer energy to the CCD silicon, which ultimately results in measured signal that is not originating from photon illumination. The signal due to the proton interactions is rst separated from the noise contribution and subsequently used in the determi- nation of a pulse height probability distribution. Separation of the noise from the proton events also leads to the measurement of proton streak lengths and orientations along with the associated probability distributions. The directionality of the space weather environment in Low Earth Orbit is examined using the distribution of proton streak angles. Statistics found from the Hubble are also used as a starting point for simulations that create synthetic proton signal images. The distributions resulting from the Hubble CCD analysis give the probability of the: number of proton events, which is related to the ux of the space weather protons; energy of proton events, which allows estimates of damaging proton interactions; length of proton streaks on the CCD, which shows the relative probability of a long traversing proton event; angle of proton event, which indicates the directionality of the space weather environment.
  • The objective of this research is the statistical study of space weather e ects on im-

    age detectors in Low Earth Orbit. The Hubble Space Telescope is used as a resource

    for acquiring proton a ected images for statistical analysis. For the purpose of the

    present work, the space weather environment will consist of cosmic as well as solar

    proton particles. The proton occurrences evident in images from the Hubble Charge

    Coupled Device (CCD) have been used to calculate the probability of proton events,

    which is related to the local space weather particle

    ux. The proton particles transfer

    energy to the CCD silicon, which ultimately results in measured signal that is not

    originating from photon illumination. The signal due to the proton interactions is

    rst separated from the noise contribution and subsequently used in the determi-

    nation of a pulse height probability distribution. Separation of the noise from the

    proton events also leads to the measurement of proton streak lengths and orientations

    along with the associated probability distributions. The directionality of the space

    weather environment in Low Earth Orbit is examined using the distribution of proton

    streak angles. Statistics found from the Hubble are also used as a starting point for

    simulations that create synthetic proton signal images. The distributions resulting

    from the Hubble CCD analysis give the probability of the: number of proton events,

    which is related to the

    ux of the space weather protons; energy of proton events,

    which allows estimates of damaging proton interactions; length of proton streaks on

    the CCD, which shows the relative probability of a long traversing proton event; angle

    of proton event, which indicates the directionality of the space weather environment.

publication date

  • August 2010