Polar PWI Sounds International Solar Terrestrial Physics (ISTP) Historical Pages

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>Collaborating Programs
>Instrument Descriptions
grey200 GOES
Instrument Descriptions

The energetic particle monitor consisted of three detector assemblies, each covering limited regions of the overall energy spectrum. The first two detector assemblies monitored protons in seven energy ranges between 0.8 and 500 MeV, and alpha particles in six ranges from 4 to >400 MeV. There was also one channel for the measurement of electrons in the >=500 keV range. The third detector, the high energy proton and alpha detector (HEPAD), monitored protons in four energy ranges above 370 MeV and alpha particles in two energy ranges above 640 MeV/nucleon.

(the following quality information was provided by Dr. Herb Sauer NOAA R/E/SE 303-497-3681) :

The GOES E1 and P1 channels were designed to measure the geostationary flux of electrons of energy E>2 MeV and protons of energy E such that .6 < E < 4.2 MeV. Because of radiation damage to the GOES-6 E1 detector, these data are not included in the data-set. The GOES -7 electron detector also responds to protons of energy E > 80 MeV. Therefore, during solar energetic particle events, the electron data are often compromised to the extent that they may primarily represent the detector response to energetic protons. GOES-7 particle detector data is missing during an eclipse and for approximately the following 4 hours. Finally, the geomagnetic cutoff at geostationary orbit is of the order of 1 MeV, which is within the energy range of the P1 channel. Therefore, the flux observed during a solar energetic particle event by channel P1 is a composite of trapped protons at the lower channel energies and event protons which reach the satellite from sources outside the magnetosphere.

(the following quality information was provided by Dr. Howard J. Singer, Acting Chief Geospace Branch, NOAA R/E/SE 303-497-6959) :

GOES 6 - Magnetometer

    A variety of malfunctions of the spin plane components (He and Hn) of this instrument have occurred since at least September 1992. These data are useful for detecting a variety of disturbances in the space environment, but the actual field values are not to be trusted. The parallel, or spin axis, component (Hp) of the field appears to be unaffected by the spacecraft or instrument difficulties; however, the offset of this component is difficult to calibrate and questionable. Interpretation of the data is also complicated by the fact that the GOES 6 spacecraft orbit has become more inclined to the equatorial plane than is typical of the GOES satellites.
GOES 7 - Magnetometer
    The GOES 7 magnetometer transverse components (He and Hn) failed on May 2, 1993. At this time an offset also appeared in the spin axis component. This offset was removed on May 18, 1993; however as with GOES 6, the absolute value of the spin axis component also has uncertainties.

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