Summary
The article first describes in chronological order the observations on the propagation of radio waves during the solar eclipses, and the development of the conflicting results on the similar transmissions of radio signals. The general theory of the absorption of radio waves in the ionosphere is briefly described and therefrom a method is derived to estimate the variation of the absorption of obliquely incident radio waves during a solar eclipse.
The variation of field-strength can be studied in terms of the relationship between the vertical incident equivalent frequency of the signals and the critical frequencies of the ionospheric layers at the regions of reflection. The total absorption of radio waves consists of the non-deviative absorption in theD region and the deviative absorption in the higher layers of the ionosphere. During the eclipse, theD region absorption decreases in phase with the progress of the eclipse, but the variation of deviative absorption may differ in each observation. The deviative absorption is large when the equivalent frequency is close to the critical frequency of the layer reflecting the waves or of the layer just penetrated by the waves. The changes in the deviative absorption during an eclipse can be estimated on the basis of the variation of the critical frequencies of the ionospheric layers. The resultant changes in the total absorption during a solar eclipse may thus be estimated. The different types of field strength variation expected during an eclipse are given.
The observations of the vertical incident absorption of radio waves and the field strength variations of obliquely incident continuous wave radio signals during the solar eclipse are described and the changes are explained on the basis of the above theory.
Similar content being viewed by others
Bibliography
Schledermann H.:Effect of solar eclipse on wireless telegraph signals. Electrician, 69, p. 329 (1912).
Kiebitz F.:Funkentelegraphische Beobachtungen während der Sonnenfinsternis an 17. April 1912. Phys. Zeit., 13, pp. 890–892 (1912).
Boutaric A. &Maslin G.:Influence de l'éclipse de Soleil du 17 avril 1912 sur la propagation des oscillations électriques. Compt. Rend. (Paris), 154, pp. 1746–1747 (1912).
Flajolet M.:Réception à l'Observatoire de Lyon, des signaux radiotélégraphiques de la tour Eiffel pendant l'éclipse de soleil du 17 avril. Compt. Rend. (Paris), 154, 1488–1491 (1912).
Turpain A.:Influence de l'éclipse du soleil du 17 avril 1912 sur la propagation des ondes électriques. Compt. Rend. (Paris), 154, 1457–1461 (1912).
Eccles W. H.:Effect of the eclipse on wireless telegraphic signals. Nature (London), 69, 191 (1912).
Pickard W. G.:The effect of the solar eclipse of January 24, 1925 on radio reception. Proc. Inst. Rad. Eng., 13, 539–569 (1925).
Galle J. B. &Talon G.:Recherches relatives à la propagation des ondes radio-électriques effectuées à l'occasion de l'éclipse du 9 mai, 1929. Compt. Rend. (Paris), 190, 48–52 (1930).
Galle J. B.:Observations relatives à la radio-électricité et en physique du globe: faites à l'occasion de l'éclipse totale de soleil du 9 mai 1929 à Paulo Condore Indo-Chine. L'onde élect., 9, 257–265 (1930).
Kenrick G. W. &Pickard G. W.:Observations of the effective height of the Kennelly-Heawiside layer and field intensity during the solar eclipse of August 31, 1932. Proc. Inst. Radio. Engrs., 21, 546–566 (1933).
Henderson J. T. &Rose D. C.:Fading and signal strength measurements taken during the solar eclipse of August 31 st. Can. J. Res., 8, 29–36 (1932).
Naismith R.:Ionospheric conditions during the solar eclipse of 19 June 1936. Proc. Phys. Soc., 49, 214–224 (1937).
Rastogi R. G. &Sheriff R. M.:A note on radio field strength observations made at Ahmedabad during the total solar eclipse on 30 June 1954. Jour. Sci. Industr. Res. (India), 14A, 159–161 (1955).
Rastogi R. G.:Studies in the Physics of the ionosphere. Ph. D. Thesis, Gujarat University (1956).
Ghosh A. K., Roy K. M., Gupta S. K., Dasgupta S. N., Sarwate V. V. &Mithal G. K.:On radio measurements at Jabalpur during the solar eclipse of 30th June 1954. Jour. Inst. Telecom. Engrs. (India), 1, 20–26 (1935).
Karpov A. N.:Change in the strength of radio signals during the solar eclipse of 30 June 1954. Priroda, Moscow, 113 (1955).
Busch R., Harnischmacher E. &Rawer K.:Observations ionosphériques effectinées durant l'éclipse solaire du 30 juin 1954 à Fribourg. Annales de Géophysique, 12, 1–15 (1956).
Royal Board of Swedish Telecommunications:Ionospheric observations during the solar eclipse of 30 June 1954 in Sweden.
Laporte J. M.:Eclipse of the sun, June 30th, 1954. Canadian Broadcasting Corporation.
Prechner L. G.:Solar eclipse of June 30, 1954 and the reception of short wave transmissions. British Broadcasting Corporation.
Fokker A. D., De Munck J. C. & De Feiter, L. D.:The influence of the solar eclipse of June 30th 1954 on some radio-telegraphic communications of the Netherlands.
National Bureau of Standards, U.S.A.: Circular No. 462 Ionospheric Radio Propagation.
Appleton E. V. &Piggott W. R.:Ionospheric absorption measurements during a sunspot cycle. Jour. Atmos. Terr. Phys., 5, 141–172 (1954).
Appleton E. V.:A method of measuring the collisional frequency of electrons in the ionosphere. Nature (London), 135, 618 (1935).
White F. W. G. &Brown L. W.:Some measurements of the reflection coefficient of the ionosphere for wireless waves. Proc. Roy. Soc. (London), A 153, 639–660 (1936).
Martyn D. F.:The propagation of medium radio waves in the ionosphere. Proc. Phys. Soc. (London), 47, 323–339 (1935).
Appleton E. V. &Beynon W. J. G.:The application of ionospheric data to radio communication problems pt. 1. Proc. Phys. Soc. (London), 52, 518–533 (1940).
Appleton E. V. &Beynon W. J. G.:An ionospheric attenuation equivalence theorem. Jour. Atmos. Terr. Phys. 6, 141 (1955).
Alcock G. M.:Ionospheric absorption at low and medium frequencies, Physics of the Ionosphere (Physical Society, London), pp. 14–19 (1955).
Beynon W. J. G. &Davies K.:Simultaneous ionospheric absorption measurements at widely separated stations. Jour. Atmos. Terr. Phys., 5, 273–289 (1954).
Defence Research Telecommunications Establishment of Canada. Canadian Ionospheric data, Ottawa January 1957, Winnipeg January 1957, Churchill January 1957.
Smithrose R. L.:The solar eclipse of 1945 and radio wave propagation. Nature (London), 157, 40–42 (1946).
Smithrose R. L.:The influence of an eclipse of the sun on the ionosphere. Jour. Brit. Inst. Rad. Engrs., 6, 82–97 (1946).
Lied F. &Arhaug T. Ionospheric absorption during the eclipse of 30th June 1954. Geophysiske Publikasjoner, 19, 29–35 (1956).
Jen C. K., Chow K. T., Lo Y. T. &Kuan C. C.:An observation on the ionosphere during the solar eclipse of July 20, 1944. Phys. Rev. 66, 226 (1944).
Bosson F., Denisse J. F., Gallet R. &Saligmann P.:Ionospheric observations during the solar eclipse of 20th May 1947. Colloques Internationaux, Relations entre les phénomènes solaires et géophysiques Lyon, 9, 117–127 (1947).
Rastogi R. G. &Sethuraman R.:Field strength measurements of radio waves during the partial solar eclipses of 14 December 1935 at Ahmedabad. Jour. Sci. Industr. Res. India, 15A, 303–305 (1956).
Rastogi R. G., Sheriff R. M. & Nanda N. G.:Some measurements of signal strength of radio waves reflected from the ionosphere during the solar eclipses of 30 June 1954 and 20 June 1955. Solar eclipses and the Ionosphere (Special Supplement to Jour. Atmos. Terr. Phys. 1956), 137–142.
Gopal Rao M. S. V. &Rao B. R.:Effect of solar eclipse of 20 June 1955 on long distance shortwave propagation. Current Science, 24, 408 (1955).
Bibl K. &Delobeau F.:Ionosphärische Beobachtungen während der totalen Sonnenfinsternis vom 30. Juni 1954. Zeit. Geophysik, 21, 215–227 (1955).
Landmark B., Lied F. &Skribeland S.:Ionospheric h′-f observations obtained during the period of the solar eclipse of 30th June 1954. Geophysiske Publikasjoner, 19, 5–28 (1956).
Stoffregen W.:The solar eclipse of 30 June 1954:Preliminary report. Solar eclipses and the ionosphere. Special Suppl. to Jour. Atmos. Terr. Phys., 57–64.
Bennington T. W.:Effect of partial solar eclipse of 1954 June 30th on propagation of G.R.C. 3975 kc/s.
Rastogi R. G.:Vertical ionospheric soundings at Ahmedabad during the partial solar eclipse of 19 April 1958. Jour. Sci. Industr. Res. (India) 18A, 123–126 (1959).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Rastogi, R.G. Propagation of radio waves reflected from the ionosphere during a solar eclipse. Geofisica Pura e Applicata 45, 123–152 (1960). https://doi.org/10.1007/BF01996580
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF01996580