The lack of open literature publication of the distributional properties of the cm-2 spectra of solar microwave bursts has lead to some erroneous concepts of the typical characteristics of these spectra. To provide more accurate information, this paper sets forth various distributions of the peak flux density spectra of large numbers of bursts, based on observations of the Sagamore Hill Radio Observatory at nine discrete frequencies between 245 and 35000 MHz over the years 1968-1971. As a foundation for the distribution studies, the basic spectral classification system is outlined. The majority of burst spectra were found to contain a cm-2 component having a single spectral maximum in the 1400 to 35000 MHz range; such spectra are designated C type. A study of the correlation of the spectral maximum frequency fm~x of the cm component and the photospheric magnetic field strength of the associated region shows a tendency for greater correlation at higher fm~x for stronger magnetic fields. A study of the correlation for C type spectra between fm~x and the quasi-cutoff frequency fq~ on the low-frequency side shows that for bursts of moderate peak flux density (50-500 sfu) fqe is well correlated with fmax; a good fit to the relation fmax--A fqc is found with A--3.4. The possible attenuating mechanisms responsible for the spectral shaping of the cm component are discussed.

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In this paper we describe the development of a model of the electron current collected by solar arrays from the ionospheric plasma. This model will assist spacecraft designers in minimizing the impact of plasma interactions on spacecraft operations as they move to higher-voltage solar arrays. The model was developed by first examining in detail the physical processes of importance and then finding an analytic fit to the results over the parameter range of interest. The analytic model is validated by comparison with flight data from the Photovoltaic Array for Space Power Plus diagnostics (PASP Plus) flight experiment [D. A. Guidice, 34th Aerospace Sciences Meeting and Exhibit, Reno, NV, 1996, AIAA 96-0926 (American Institute of Aeronautics and Astronautics, Washington, DC, 1996)].

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