The ionospheric propagation of low- and very-low-frequency radio waves over distances less than 1000 km

Bracewell, R. N.; Budden, K. G.; Ratcliffe, J.A.; Straker, T.W.; Weekes, K.

doi:10.1049/jiee-2.1951.0087

Cited by 24 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The apparent discrepancy between the calculated ionospheric virtual height values can be attributed to the fact that ionospheric virtual heights for obliquely incident radio waves area function of frequency with lower frequency waves being reflected from lower virtual heights. The median value of 91.0 km MSL for the field change emissions, which are VLF/LF radio waves, is consistent with results reported by Appleton and Burnett [1925] and Bracewell et al [1951] for obliquely propagated VLF/LF waves over paths of similar lengths during the night. The median value of 101.6 km MSL for the broadband HF emissions is consistent with results from Marty et al [1934].…”

Section: Observations From All Three Stormssupporting

confidence: 90%

Compact Intracloud Discharges

Smith¹

1998

View full text Add to dashboard Cite

Section: Observations From All Three Stormssupporting

confidence: 90%

Compact Intracloud Discharges

Smith¹

1998

View full text Add to dashboard Cite

“…Reasonable values of these parameters for the 1 ionosphere for VLF have been determined from experi-I mental data by Murphy [1956,1957], Budden I [1951], Bracewell et al [1951], and Crary [1961]. I These values are: for night Wr = 5 X 10 5 , 7 = 60°, and I h'=90 km; for day wr=1.5x105, 7=15°, and h' = 74 km.…”

Section: Calculation Of the Exchanges In Phase Andmentioning

confidence: 99%

Effect of the eclipse of 20 july 1963 on VLF signals propagating over short paths

Crary¹,

Schneible²

1965

J. RES. NATL. BUR. STAN. SECT. D. RAD. SCI.

View full text Add to dashboard Cite

Measurements were made at Hanover, N.H., of the effect of the solar eclipse of 20 July 1963 on the phase and amplitude of two VLF signals propagated over relatively short paths . The skywave signal from NAA, Cutler, Maine, (14.7 kc/s) was refle cted once from the D region at a point of total optical obscuration. The skywave signal from NSS, Annapolis, Md. , (22.3 kc/s) was reflected from a point where the maximum optical obscuration was 88 percent. Chan ges in the phase and amplitude of the signals during the eclipse range d from about 40 percen t to 100 percent of the diurnal variation. The times of the maximum phase and amplitude effects were used to c alculate effec tive recombina· tion coefficients for th e ionosp here. The maximum amplitude of VLF signals occurred before the time of maxi mum optical obscuration. This ca n be attributed to a specific so urce of ionizing radiation above the s un 's west limb, which would be uncov ered before the optical maximum. The calc ulate d effec tive reco mbination coeffi cient is about 2 X 10-5 . This value is closer to th e valu e of approximately 3 X 10-6 , calc ulated from theory by Crain [1961] for the nighttime ionosphere, than to Crain's daytime value. Most values of recombination coefficients from previous radio experim e nts are closer to Crai n's daytime values .

show abstract

“…Systematic radio-reflection observations of the D-region were pioneered (Bracewell et al, 1951) in the United Kingdom after World War II. During the 1960s there appeared both excellent summaries of two decades of observations, and sophisticated, full-wave numerical models of the radio propagation (e.g.…”

Section: Introductionmentioning

confidence: 99%

“…The narrowband radio-link approach is well typefied by the 16-kHz observations (Bracewell et al, 1951) on the Rugby-to-Cambridge path, which were later summarized and compared to results of a full-wave model (Piggott et al, 1965). The narrowband technique is unable to discriminate partial reflections from "full" reflections.…”

Section: Introductionmentioning

confidence: 99%

Low-frequency ionospheric sounding with Narrow Bipolar Event lightning radio emissions: energy-reflectivity spectrum

2008

View full text Add to dashboard Cite

Abstract. We analyze data on radio-reflection from the D-region of the lower ionosphere, retrieving the energyreflection coefficient in the frequency range ∼5-95 kHz. The data are the same as developed for a recent study of ionospheric-reflection height, and are based on recordings of powerful (multi-Gigawatt) radio emissions from a type of narrow (∼10 µs) lightning discharge known as "Narrow Bipolar Events". The sequential appearance of first the groundwave signal, and then the ionospheric single-hop reflection signal, permits us to construct the energy-reflection ratio. We infer the energy reflection's statistical variation with solar zenith angle, angle-of-incidence, frequency, and propagation azimuth. There is also a marginally-significant response of the energy reflectivity to solar X-ray flux density. Finally, we review the relationship of our results to previous published reports.

show abstract

The ionospheric propagation of low- and very-low-frequency radio waves over distances less than 1000 km

Cited by 24 publications

References 0 publications

Compact Intracloud Discharges

Compact Intracloud Discharges

Effect of the eclipse of 20 july 1963 on VLF signals propagating over short paths

Low-frequency ionospheric sounding with Narrow Bipolar Event lightning radio emissions: energy-reflectivity spectrum

Contact Info

Product

Resources

About