Cosmic Radio Noise Intensities in the VHF Band

Cottony, H.; Johler, J. R.

doi:10.1109/jrproc.1952.273872

Cited by 23 publications

(2 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Eq uation (17) illustr ates t he defini tion of L p , the p7'opagation l088, i. e., th e tr ansmi ssion loss expected if the a ntennas h ad gains an d circui t resistances the sam e as if th ey were in free space. More generally, L, and Lr are defin ed as (18) wh ere r' is th e act ual r esistance of th e a ntenn a in th e presence of its environmen t and r f is th e radiation resistance i t wo uld h ave h ad if i t were in fr ee space, ~Wh e n we note th at L, a nd L r m ay var y s ubstan tially from one antenn a in stall ation to th e n ext, depending upon th e circui t losses, polar ization, ground co ndi tions, wheth er 0 1' n ot a ground screen is used, and upon oth er environmental factors s uch as th e presence of trees 01' ovcrhead wir es, it becom es clear why it is de irable to separate these compon ents from the system loss and to have a propagation loss, L 7 J) independent of these antenna •environmental conditions.…”

Section: Influence Of the Antenna Environment And Definition Of Propamentioning

confidence: 99%

“…. Using the results in a rece nt paper by Cottony and JollieI' [18], values of f a may also readily be determined for cosmic radio noise simply by dividing their eq uivalent blackbody temperatures by 288.48. It should be noted tbat f a will usually be somewhat d epend ent upon the r eceiving an te nna direc tivity and the published values of fa quoted above correspond to reception on a short vertical electric antenna in references [16] and [17] and to reception on a horizontal half-wave electri c dipole in [18].…”

Section: Percentage Of Time That a Desired Signal Is Free Of Interfermentioning

confidence: 99%

See 1 more Smart Citation

System loss in radio wave propagation

Norton¹

1959

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

View full text Add to dashboard Cite

A summary is prese nted of the ways in whi ch the concept of system loss a nd the close ly related concepts of transmission loss, basic transm iss io n loss, propagation loss, and pat h ~ntellna gain ma y be used for precise, yet s imple, description s of so me of t he characteris tics of rad io wave propaga tion which are important in t he des ign of rad io syste ms. D efini t ions of various terms associated with the co ncept of syste m loss a re give n which in trodu ce a greater fl exibility into its use without any loss in precis ion. I t is shown t hat t he usc of thC'se added terms and concepts ma kes feasible the extens ion of the usc of t his method of descript ion t o a ny portion of the ra dio spectrum. A more general formula for the syste m loss is give n which may be used for anten nas with an arbitrarily sma ll separa t ion. Usin g t his formll l~ it is shown that t he syste m loss betwee n s m~ll elect ric or magnet ic dipoles separated by a distance d « A can be made arbitrarily small even though t he individua l a nte nn as have la rge circuit losses. Formulas are developed for the perce ntage of t im e t hat a des ired signal is free of in terference, a nd these a re used to demonstrate methods for t he e ffi cient use of the spectrum. In particula r, contrary to general belief, it is show n t hat efficie ncy is promoted by t he use of high power a nd hi gh ant~nnas and, in the case of a broad cast ser vice, s uffici ent ly srnall separations so t hat t here is appreciable mu t ual in terfe re nce. A n a na lys is is mad e o f t he varia nce of t he path a ntenna gain in ion osp heri c scatter propagation. Met hod s a re g ive n for t he calculatio n of the tra ns mi ssion loss for t he gro und wave an d tropospheric scatter modes of propagation thro ugh a turb ul ent model at mosphere w it h a n expo nen t ia l grad ient. Examples of such calculation s are g iven which cover a wide ra nge of frequ cncies a nd antc nn a heights. Finall y, cxamples are given of t hc expected ra nge o f various t ropospheric poin t-to-point scatter syste ms s uch as a n FM m ul t icha nn e l teletype systcm, a telev ision relay or a n FM br oadcast relay.

show abstract

Section: Influence Of the Antenna Environment And Definition Of Propamentioning

confidence: 99%

Section: Percentage Of Time That a Desired Signal Is Free Of Interfermentioning

confidence: 99%

System loss in radio wave propagation

Norton¹

1959

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

View full text Add to dashboard Cite

show abstract

An Hf-Radar Search for the Effects of Earth Satellites Upon the Ionosphere

Croft

Villard

1965

Interactions of Space Vehicles With an Ionized Atmosphere

View full text Add to dashboard Cite

Radio-Astronomy and Navigation

Cade¹

1958

J. R. Aeronaut. Soc.

View full text Add to dashboard Cite

The difficulties of determining latitude and longitude under adverse weather conditions, when neither the Sun nor stars can be sighted, are well-known, and the advantages of a non-visual system of position finding which could operate through clouds or fog are too obvious to require emphasis.A Radio Sextant, which detects and locks-on to 8 mm. radiation from the Sun, has already been made and tested in America with reputedly excellent results. An analysis of both the theoretical and the practical design factors is given in the present paper, together with the results of successful experiments made in Great Britain.

show abstract

Cosmic Radio Noise Intensities in the VHF Band

Cited by 23 publications

References 21 publications

System loss in radio wave propagation

System loss in radio wave propagation

An Hf-Radar Search for the Effects of Earth Satellites Upon the Ionosphere

Radio-Astronomy and Navigation

Contact Info

Product

Resources

About