Accession Number : AD0717792

Title :   Riometer Studies of the Interrelations of Radio Noise and Absorption.

Descriptive Note : Final rept. 1 May 69-30 Apr 70,

Corporate Author : NEWCASTLE UNIV (AUSTRALIA) DEPT OF PHYSICS

Personal Author(s) : Ellyett,Clifton D. ; Roberts,Ronald H.

Report Date : JUL 1970

Pagination or Media Count : 15

Abstract : Tentative riometer data recorded at Christchurch, New Zealand, during 1960-61 indicated that cosmic noise absorption measurements sometimes appeared to show a gradual increase for one or two days prior to a major flare. The hypothesis was made that a possible cause could be a slow increase in solar X-ray activity. Since 1966 accurate riometer studies have been made at Newcastle, N.S.W., Australia. It would appear, from recent satellite data, that there is, at least in a number of cases, a slow build-up of solar X-ray emission prior to a significant flare. Any associated absorption changes measured at mid-latitudes, however, are so slight that it calls for almost impossibly high riometer stability. A more useful indicator is likely to be the continuous direct satellite monitoring of solar X-ray emissions. Observations are being continued with an extensive aerial array giving a narrow beam, with negligible side lobes, tilted electronically south of the zenith to exclude direct solar noise. (Author)

Descriptors :   (*RADIOFREQUENCY INTERFERENCE, SOLAR RADIATION), (*SOLAR FLARES, PREDICTIONS), X RAYS, RADIO WAVES, ABSORPTION, RIOMETERS, AUSTRALIA

Subject Categories : Astrophysics
      Radiofrequency Wave Propagation

Distribution Statement : APPROVED FOR PUBLIC RELEASE