Accession Number : AD0652506

Title :   ARECIBO IONOSPHERIC OBSERVATORY.

Descriptive Note : Final rept. no. 10, 1 Feb 64-31 Jan 67.

Corporate Author : CORNELL UNIV ITHACA N Y CENTER FOR RADIOPHYSICS AND SPACE RESEARCH

Report Date : 31 JAN 1967

Pagination or Media Count : 148

Abstract : The final report summarizes the research at the Arecibo Ionospheric Observatory from 1 Feb. 1964 to 31 Jan. 1967. A table summarizes the accomplishments of the various programs. The ionospheric studies include incoherent backscatter measurements of electron density to 1500 km, derivation of ionic composition and of electron and ion temperatures as a function of height. Important discoveries include the plasma line, the influence of photoelectrons produced at the magnetic conjugate point, and traveling wavelike disturbances. The radar astronomy studies have shown topographical features on Venus and Mercury, the retrograde rotation of Venus with a 249 day period, and the extremely small radar cross section of Jupiter. Surprisingly, Mercury has been found to have a period of rotation 2/3 that of its orbital period. The range-Doppler technique used to map the moon has given resolutions of 5-10 km. In the radio astronomy studies, 70 lunar occultations of celestial radio sources were measured, interplanetary scintillations were studied, and flux densities of a large number of radio sources were determined, as well as the brightness of many ionized hydrogen regions in galactic space. It was concluded that the AIO instrument will exceed the capabilities of other instruments for some time and can be easily improved to operate at much shorter wavelengths. (Author)

Descriptors :   (*IONOSPHERE, *ASTRONOMICAL OBSERVATORIES), MEASUREMENT, INCOHERENT SCATTERING, ELECTRON DENSITY, IONS, TEMPERATURE, RADIO ASTRONOMY, TERRAIN, VENUS(PLANET), MERCURY(PLANET), DENSITY, SCINTILLATION, BRIGHTNESS, PHOTOELECTRONS, INSTRUMENTATION, PLASMAS(PHYSICS), TABLES(DATA), MAPS

Subject Categories : Astrophysics
      Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE