Satellite scintillation observations at Boulder, Colorado

Jespersen, J.L.; Kamas, G.

doi:10.1016/0021-9169(64)90027-3

Cited by 34 publications

(11 citation statements)

References 24 publications

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“…It is of interest to compare the results of the present investigation with those of McClure [1964]. His curve, which is shown as the dotted line in Figure 4 latitude has also been reported by Jespersen and theoretical studies that for a fixed satellite height Kamas [1964]. a maximum scintillation is observed when the height On several occasions the observed scintillation of irregularities is halfway between the satellite and pattern appeared to have a very regular or sinusoidal the ground.…”

Section: In Reducing the Data Many Records Showed Patchy Regions Of Ssupporting

confidence: 82%

Measurement of Irregularity Heights by the Spaced Receiver Technique

Paul¹,

Yeh²,

Flaherty³

1970

Radio Science

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Scintillation of radio signals from an artificial earth satellite has been analyzed using the spaced receiver technique in order to gain a greater understanding of the latitudinal and diurnal variation of the height of the electron irregularities responsible for the observed scintillation on the ground. a r e also noted.nighttime hours than during the midday hours. Also, the average i rregularity height increases towards the north. This increase appears to be due to the existence of small patches of irregularities occurring a t higher heights to the north. A large portion of the data falls in the 300-450 km range and thus confirms the observations of others. Other prominent features of the scintillationThe irregularity heights tend to be greater during the A regular type of fading has been observed on many occasions. This regular scintillation is compared t o that observed by others and an argument is presented which tends to refute use of the sharp edge diffraction model a s an explanation for this phenomenon. Also, irregularity patches a t the same sub-ionosphere latitude but a t different heights were observed and this phenomenon is discussed.

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Section: In Reducing the Data Many Records Showed Patchy Regions Of Ssupporting

confidence: 82%

Measurement of Irregularity Heights by the Spaced Receiver Technique

Paul¹,

Yeh²,

Flaherty³

1970

Radio Science

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“…the 'scale of the irregularities' and as 'irregularity size' by more recent authors[Briggs and Parkin, 1963;Jesperson and Kamas, 1964]. Since its relation to Lr is simply the factor 1/2 •r, the autocorrelation distance or irregularity size found by our measobserved at low-elevation angles (subauroral latitudes) and axial ratios of 12 at high-elevation angles (middle latitudes).…”

supporting

confidence: 56%

“…Frihagen [1963] found the irregularity size (L•) transverse to the earth's magnetic field to be no greater than 12 kin. Jesperson and Kamas [1964] in measurements at Boulder, Colorado, just below the subauroral zone found the irregularity size to be of the order of 1 km. At the equator, Koster [1963] has found transverse (east-west direction) irregularity size L• to be of the order of 0.5 km, with axial ratios of 7.5 or greater.…”

mentioning

confidence: 98%

“…Measurements using signals from satellites [Frihagen and Troim, 1960;Frihagen, 1963;Jesperson and Kamas, 1964] have found the height of F-region irregularities to be almost always in the range 300 to 500 km. Let us take 400 km as the height of the irregularity-layer and 10 minutes as the radio source angular diameter A0 at which the scintillation index declines to 0.5 of its value for a point source.…”

mentioning

confidence: 99%

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The size of low-latitude ionospheric irregularities determined from observations of discrete sources of different angular diameters

Aarons¹,

Guidice²

1966

J. Geophys. Res.

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Several methods have been used to measure the horizontal dimensions of ionospheric irregularities that cause the scintillation of radio signals propagating through the terrestrial ionosphere. A frequently used technique is to measure the size of the shadow pattern on the ground with spaced receivers using a very strong radio source (usually Cassiopeia A or Cygnus A) or a satellite as the source of radio frequency energy. The technique described in this paper is to utilize the differences in the angular diameter of various discrete radio sources to determine irregularity size. The phenomenon, by which a radio source of small angular diameter scintillates while one of large angular diameter does not, is directly analogous to the optical portion of the electromagnetic spectrum where stars scintillate but planets do not.

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“…One feature of these artificial scintillations, however, differs from that of natural scintillations in that there appears to be a systematic variation in the period from about 3 to about 11/2 s during the transition of the satellite pass from north to south. Using orbiting satellites, Jespersen and Kamas [1964] observed natural scintillations at Boulder, and they were unable to find significant differences between the northern and the southern regions of observation. In another study, observations of natural scintillations of satellite signals at 137 MHz were made by using the NOAA satellite acquisition station at Gilmore Creek, Alaska [Pope and Fritz, 1971].…”

Section: The First Observation Of Artificial Scintillations By Means mentioning

confidence: 98%

Observations of artificially produced scintillations using satellite transmissions

Pope¹,

Fritz²

1974

J. Geophys. Res.

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The ionospheric modification experiment, utilizing a high‐powered transmitter located near Platteville, Colorado, provides an opportunity to study ionospheric irregularities under relatively known conditions. The irregularities were studied by means of transionospheric signals from the polar‐orbiting satellite Essa 8 transmitting at 137 MHz. These observations show that scintillations occur when the satellite to ground station geometry is such that the ray from the satellite passes through the region in the ionosphere under modification. In general a cut across the illuminated volume is obtained; thus an active region about 100 km in diameter is indicated, roughly in agreement with the projection of the transmitter half‐power cone. For the most part the artificial scintillations appear to be similar to those obtained from naturally occurring irregularities, but a systematic change from 3 to 1 s in the fluctuation period is usually observed as the satellite traverses from the northern to the southern portions of the active region. The change in period appears to be produced by a systematic change in irregularity scale size from about 4 to about 1 km.

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Satellite scintillation observations at Boulder, Colorado

Cited by 34 publications

References 24 publications

Measurement of Irregularity Heights by the Spaced Receiver Technique

Measurement of Irregularity Heights by the Spaced Receiver Technique

The size of low-latitude ionospheric irregularities determined from observations of discrete sources of different angular diameters

Observations of artificially produced scintillations using satellite transmissions

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