HR: 0800h
AN: SM41A-1171    [Abstracts]
TI: A Four-Year Data Study of CEASE as Compared to the GOES Satellite at Geosynchronous Altitude
AU: * Knorring, C
EM: Christine.Knorring@hanscom.af.mil
AF: Air Force Research Laboratory, 29 Randolph Rd., Hanscom AFB, MA 01731 United States
AU: Golightly, M
EM: Michael.Golightly@hanscom.af.mil
AF: Air Force Research Laboratory, 29 Randolph Rd., Hanscom AFB, MA 01731 United States
AB: The Compact Environmental Anomaly Sensor (CEASE) is a small, autonomous, lightweight instrument presently operating on a Department of Defense geosynchronous satellite. Developed by the Air Force Research Laboratory, CEASE maintains space situational awareness to provide real-time hazard warnings to the host spacecraft and also aids in radiation belt model development. The CEASE in geosynchronous orbit was launched in August 2001 and since activation, has continuously collected data. Equipped with two dosimeters, a particle telescope, and an electrostatic analyzer, it measures protons and electrons that cause the following anomalies: surface and deep dielectric charging, SEUs (Single Event Upsets), and radiation rate and dose effects. The two dosimeters measure particles in twelve channels: Dosimeter 1 is located behind a 0.20-cm thick Al shield and Dosimeter 2 behind a similar 0.63-cm thick Al shield. The energy deposited by each incident particle is measured and then identified as a Low Linear Energy Transfer (LOLET, 50 KeV<E_p<1 MeV) or a High Linear Energy Transfer (HILET, 1 MeV<E_p<10 MeV) type. These bins help discriminate between electrons and protons as well as determine the energy of each particle. Each dosimeter has a mixed response to protons and electrons. Numerical modeling, ground calibration and comparison to in-flight data from instruments on the Geosynchronous Operational Environmental Satellite (GOES) shows that the Dosimeter 2 HILET B channel responds primarily to protons while the Dosimeter 1 LOLET channel responds mainly to electrons, as determined by the amount of energy deposited into the dosimeters. One event of notable activity was the Halloween storm of 2003, in which the two aforementioned channels were visibly affected with incident particle intensity about 1000 times higher than the average over the four year period. These elevated levels were only exceeded by the major electron belt enhancement recorded by CEASE in July and early August of 2004. Dosimeter 1 LOLET, the electron channel, maintained a relatively constant rate for most of the four year period, with the exception of one year, from April '03 to April '04, in which much higher general levels of flux activity were observed.
DE: 7974 Solar effects
DE: 7984 Space radiation environment
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005