the big pulkovo radio telescope and pulkovo radio astronomy

Astron. Nachr. / AN 328, No. 5, 405 – 410 (2007) / DOI 10.1002/asna.200710764

The Big Pulkovo Radio Telescope and Pulkovo radio astronomy

Y.N. Parijskij�

Special Astrophysical Observatory, Nizhnij Arkhyz, Zelenchukskaya, Karachaevo-Cherkessia, Russia 369167

Received 2007 Mar 21, accepted 2007 Mar 21Published online 2007 May 15

Key words history and philosophy of astronomy – telescopes

In this paper the history of the Pulkovo Radio Telescope and its successor the Ratan-600 facility is described. Interwovenin this description are the developments in the Russian radio astronomy from the early beginnings 60 years ago up till thepresent.

c© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

1 Introduction

Radio Astronomy in the USSR has started with secret exper-iments on radio wave propagation carried out before 1947.The German radio telescopes known as the ‘Big Wurzburg’and the Phased Array ‘SCR-627’ were used in Crimea forthis purpose, as well as several interferometers. In 1953I.S. Shklovskij collected all available world information inthe ‘Radio Astronomy Lectures’ published later as ‘CosmicRadio Waves’ (Shklovskij 1956). This book triggered RadioAstronomy in the USSR, as well as in some other countries.V.L. Ginzburg, I.S. Shklovskij, S.B. Pikelner, S.A. Kaplan,S.I. Sirovatskij and later the Y.B. Zeldovich group createdthe theoretical fundament of the Russian Radio Astronomy.This helped greatly in the quick progress in instrumentation.In the 1950s several large world-class instruments were con-structed in Russia:

– the RT22 for millimeter waves,– the big Pulkovo Radio Telescope (BPR) 130 m×3 m

MMT for centimeter waves,– a cross telescope in Pushino 1000 m×40 m for meter

waves,– the great Kharkov cross for decameter waves.

The start of the Radio Astronomy in Russia was con-nected with the solar eclipse in Brazil in 1947, with theconfirmation that a HOT Solar corona really exists. Aca-demician Alexander Alexandrovich Michailov, director ofthe Pulkovo Observatory (1947–1963), was the head of theexpedition to Brazil for observation of the solar eclipse(20.05.1947). Semen Emmanuilovich Khaikin, the deputydirector of the Brazil expedition and professor of theMoscow State University, realized this experiment and be-came later the most active person in the Soviet experimentalRadio Astronomy.

� Corresponding author: [email protected]

Fig. 1 Academician Alexander Alexandrovich Michailov (left),the director of the Pulkovo Observatory (1947–1963), and SemenEmmanuilovich Khaikin (right), professor at the Moscow StateUniversity, were the leading figures of the early radio astronomyin the USSR.

Actually the first radio astronomer in Russia was A.Popov (1897), with his 100 m2 antenna for ‘Nature-to Peo-ple’ communication, a so-called ‘Thunderstorm Marker’.S.E. Khaikin was the most active person in organiza-tion of Radio Astronomy in Crimea, Moscow, Gorkij andLeningrad. In many respects he was the ‘Russian equivalentof John Bolton’ in Australia and the USA.

2 Big Pulkovo Radio Telescope (BPR)

The history of the ‘Big Pulkovo Radio Telescope’ (BPR) isnon-trivial, and its role in the National Radio Astronomyis visible even now. A concept of the instrument (Khaikin& Kaidanovskij 1959) appeared as an opposition to stan-dard approaches. Many features were new for the radio as-tronomers community of the beginning of the 1950s:

1. It used microwaves instead of meter-waves.2. It was a ‘multi-mirror’ telescope (MMT) instead of a

single construction.

c© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

406 Y.N. Parijskij: The Big Pulkovo Radio Telescope and Pulkovo radio astronomy

Fig. 2 The ship ‘Griboedov’ with a radio telescope on board,1947, Brazil. The 96-dipole array at wavelength 1.5 m was used asthe radio telescope with one freedom of motion (elevation angle).The azimuthal rotation was achieved by very accurate rotation ofthe ship itself, suggested by S. Khaikin.

Fig. 3 1954–1956: the construction of the Big Pulkovo Radiotelescope (top) and the Radio Astronomy department building(bottom). During the World War II, the front crossed this part ofthe Pulkovo hill, and there were some problems with many unex-ploded mines and charges.

3. It moved from standard limits of the single dish accu-racy (ε/D ∼ 10−4) to the limits of classical geodesicmethods (ε/D ∼ 10−6).

The Pulkovo BPR consisted of absolutely identical andvery simple reflecting elements with 3 degrees of freedom,1.5 m×3 m in size each, which were located on a 100 mradius arch. This telescope operated in the 3–30 cm wave-length range. The physical area of antenna was equal tothe 25 m dish, but the HPBW resolution corresponds to a130 m×25 m elliptical mirror at a high elevation angle. Theantenna pattern was a fan beam with 1 arc minute 3 dB beamin azimuth at λ3 cm. Later with improved panels λ8 mm ob-servations were realized with a 15 arc seconds 3 dB one-dimensional resolution. Elements of variable profile of the

Fig. 4 The Big Pulkovo Radio Telescope in operation. Photo byA.A. Mikhailov.

Fig. 5 The ‘CHEESE’-type feed system which illuminated themain surface by cylindrical wave front. The main surface is apart of the Elliptical Cone which converts a cylindrical wave frontinto a plane wave front. This feed type was used for two frequen-cies only (3.2 cm and 8.3 cm). Later it was replaced by the ‘Hein-rich Hertz parabolic cylinder’, symmetrical and ‘open’, with manyfeeds along the focal line.

aperture at different elevations, inside the ‘elliptical cone’family, and ADAPTIVE arrays (quick control by sphericalwave front, constructed by geodesy and later by auto colli-mation and focal field HOLOGRAPHY) methods were pos-sible in the Pulkovo-type solution. It was shown that a verybig telescope can be constructed by this way without anymechanical problems.

3 The Pulkovo radio astronomy: the firstdecade, 1954–1964

The BPR was to be the main instrument for a new RadioAstronomy department in the Pulkovo Observatory. Wait-ing for new high-resolution facilities, few small (4 m) disheswere used efficiently. They were presented by the Lebe-dev Physical Institute in Moscow. Two discoveries weremade: a strong polarization of the Sun spots at cm waves

c© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim www.an-journal.org

Astron. Nachr. / AN (2007) 407

Fig. 6 The first generation of the Pulkovo Radio astronomers.From left to right: Dmitrij Korolkov, Vera Ikhsanova, TamaraEgorova, Semen Khaikin, Naum Kaidanovskij, Yuri Shakhbazian,Yuri Parijskij, Igor Gosachinskij in front of BPR and the 12-mdish. Today Naum Kaidanovskij is the oldest radio astronomer inthe world (∼100 years old!).

(Kaidanovskij et al. 1957) and the extra sky noise of ∼4 K(Shmaonov 1957), which was certainly above all theoret-ical predictions for the atmosphere and the Galaxy. Thisnoise was stable and isotropic. The first result had a greatinfluence on the Pulkovo Radio Astronomy (and is still aninfluence up to now). The second ‘pre-BPR’ result was un-derstood only 10 years later – it was the CMB.

High resolution of the BPR, even in the transit mode,resulted in progress in many fields of Radio Astronomy.

The Solar system: The first regular (up to now) 1 arcminute strip scans of the Sun at cm waves (Ikhsanova1959). The first detection of the Moon polarization (Sobol-eva 1962) resulted in the high accuracy dielectric constantdetermination for the lunar surface. The first strip scansof the planet Venus at 3.2 cm and 8 mm (Korolkov et al.1963) and demonstration of the limb darkening (implyingthe ‘cold and dense atmosphere above hot surface’ modelhas as against the ‘cold surface and hot ionosphere’ model).

Galaxy: the first multi-frequency resolution of theGalaxy Centre region with thermal and non-thermal compo-nents (Parijskij 1959); the first morphological catalog of allGalactic radio sources, discovered with small dishes (Pari-jskij et al. 1967); 21 cm mapping of the Northern Sky withhigher resolution (Bystrova & Rakhimov 1976).

Extragalactic: many large radio sources were resolvedfor the first time by direct single-dish observations (not byinterferometry only) (Zkharenko et al. 1963; Parijskij &Prozorov 1964); multi-frequency high resolution polariza-tion measurements (Soboleva 1966) revealed the existenceof a strong ‘Faraday Halo’ around radio galaxies; the firstattempts to measure the predicted S-Z effect; the first CMBanisotropy measurements with mK sensitivity (I, Q, U) (Par-ijskij et al. 1967; Parijskij & Pyatunina 1970).

We should add the discovery of recombination lines in1963–1964 (Dravskich et al. 1964) to the list of Pulkovosuccesses.

Fig. 7 The Sun rotation effect (copy of a presentation by V.Ikhsanova to IAU Commission 40, 1959).

Fig. 8 The first resolution of the Sgr A. The non-thermal andthermal components are seen (now well known as the ‘East’ and‘West’ components). From Parijskij (1959).

Fig. 9 The first attempt of observation of the Compton scatter-ing of the CMB photons on hot electrons in the Coma Cluster ofgalaxies (the -Zeldovich effect). From Parijskij (1973).

4 Looking for the bigger radio telescope: anSKA proposal in the 1960s

Several variants of the BPR of larger size were suggestedafter construction of the Pulkovo radio telescope, for RadioAstronomy, for the Deep Space program, and for the De-fense Ministry, with collecting surface up to 3 000 000 m2.In the early 1960s, J. Bolton organized the IAU Commis-sion 40 Working Group to find the best solution for an In-ternational Radio Telescope. The Pulkovo Group (with S.E.

www.an-journal.org c© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


Khaikin as the leader) suggested a very large variant of thefirst Pulkovo Radio Telescope. Each panel of the main sur-face was to be as large as was suggested by other interna-tional groups for single dishes (∼100 m), and the diameterof the RING should be ∼20 km (limited by troposphericalseeing), giving a resolution ∼1 arcsec. This suggestion wasmade at the IAU General Assembly meeting of Com. 40(1964, Hamburg), with a suggested site in India or in Africa(see details in Khaikin et al. 1964, 1967). S.E. Khaikin usedanalogy with optics in radio. He divided all instruments intotwo groups: reflectors (making an image in the open air)and refractors (making an image in some media: glass, ca-bles). Losses and temperature-frequency dependent refrac-tion suggested preference to reflectors. But it was clear thatreflector size, even for a Pulkovo-type system, is limited byatmosphere (phase and amplitude losses). In addition thereare problems with the field of view due to aberrations. Newsolutions were under discussion in the Pulkovo group. Someresults are summarized in the next section.

5 The ‘by-products’ of the experience withBPR

There are several important ‘by-products’ of the Pulkovo-type ideology.

1. The formation of the beam with 130 m aperture at 3 cmoccurs at 1 million km from the Earth, and a new ‘near-field zone’ method was developed and used in many ap-plications. The range of the near-field zone is ∼ D2/λand for the very large D, ‘3D’ Radio Astronomy mayappear. It was suggested that for radio telescopes of thenext generation, unlimited in size, the whole Universemay be put into the near-field zone, and a new cosmol-ogy with direct measurements of R(z) may be possi-ble. It was an instrument for direct measurement of themodel-independent Universe expansion law. The roleof the L-term may be checked (or quintessence) in themodern terminology at any z (Parijskij 1970; Kardashevet al. 1973).

2. An unusual aperture shape demands deep exploration ofpolarization effects in the reflectors. Vector focal fieldcorrection was introduced, and general theory of polar-ization effects for any shape of the main mirror appeared(Esepkina et al. 1973 and references therein).

3. The small transit time with high resolution had tobe compensated by a high receiver sensitivity. Greatprogress was well made in this field and the Pulkovogroup was leader in the USSR in low-noise receiver con-struction (Esepkina et al. 1973) and references therein).

4. The very important ‘Pulkovo surface control group’suggested several new methods of panel adjustmentswith up to 50 microns accuracy, and now it is pos-sible to check the surface by HOLOGRAPHY veryquickly. From the very beginning the ‘reference wavefront’ was constructed by classical 100-meter long wire,but soon radio physics and real holography were used.

Fig. 10 The Pulkovo School Receivers progress. The devel-opment from simple super heterodyne receivers to the travelingwave tube with 30% band, to cryogenic parametric amplifiers andHEMT receivers, up to an attempt to use big focal field MATRIXsolutions.

Now 100 µm accuracy was demonstrated at 600-meterRATAN-600 radio telescope with the Ryle-type holog-raphy.

5. With high receiver sensitivity the atmospheric noise be-gan to dominate, and an ‘anti-atmosphere’ group wasformed, with an elegant suggestion to use the size of theinstrument for filtration of the atmospheric noise (usingthe near-field zone approach). In this method, the greatersize of the radio telescope, the better atmosphere noisefiltration may be realized. If in interferometry the filtra-tion of atmosphere noise is connected with absence ofcommon emitting particles, in the near-field zone caseall emitting particles are the same in the dual beam ordual frequencies mode of observations.

6. Phase fluctuations in atmosphere restrict size of thePulkovo-type systems, and it was suggested to escapefrom this limit in the next-generation Global Arrayof the telescopes, using the HOLOGRAPHY methodof restoration of the wave front by the nearby pointsources. The Global Radio Telescope project appeared(Khaikin et al. 1964), with the Soviet POLIGAM ver-sion (Alexeev et al. 1980), which was transformed to‘QUASAR’ project (Finkelstein et al. 2005), realized bythe Pulkovo School group.

6 The Ratan-600 telescope

The increasing importance of the radio window in astron-omy, supported by the discovery of the most energeticevents in the Universe (radio galaxies) and several new pop-ulation of objects (e.g. quasars) led to an active discussionabout the future of radio astronomy in the USSR in the1960s. Some large world radio telescopes were built (e.g.Kharkov cross, Serpukhov cross) for low radio frequen-cies and a 22-m dish for mm wavelength (in Pushino). The


Astron. Nachr. / AN (2007) 409

Fig. 11 A new version of BPR – RATAN-600 (the Northern Caucasus), the worlds largest continuous aperture (see http://www.sao.ru),with 20 000 m2 geometrical surface and 600 m in diameter.

main discussion pertained to the needs for cm-wavelengthradio astronomy. Several projects were in discussion: a bigdish, an Arecibo-type bowl, and a BPR-type of radio tele-scope. Pulkovo-type radio telescopes attracted the atten-tion of the Defense Ministry for tracking and monitoringof distant rockets. A 100 000 m2 variant of the BPR wasquickly designed. The Academy of Science of the USSRselected a smaller variant, a 600-m diameter instrument,with specified surface accuracy good for λ8 mm operation.There were several ‘bloody’ discussions connected with thistype of instrument but item-to-item comparison of the ex-pected astrophysical results made an expert commission se-lect the Pulkovo project. Integration of Pulkovo ‘circle’ vari-ant with Steinberg Astronomical Institutes suggestion of a‘flat + parabola’ variant for Sky Survey mode of observationwas strongly supported by I.S. Shklovsky and N.S. Karda-shev. The Moscow group joined the RATAN-600 Pulkovoproject. The Ratan-600 telescope is described in Khaikin etal. (1972).

Looking back let me make some personal points.

1. It seems to me that two opposite views collided in the1960s: ‘let us follow the technology suggested fromabroad’ and ‘let us try to find our own way’. The firstapproach may be safe but it is always lagging behind theoriginal projects. The second way could lead to wrongdecisions.

2. We were happy to find a solution for radio astronomyfree from technological problems. We were aware of thevery promising aperture synthesis as demonstrated byMartin Ryle in Cambridge in the early 1960s but thiswas too advanced in technology for the USSR. We alsofollowed the discussions that led to the construction ofthe Westerbork Synthesis Array in Holland and the VeryLarge Array in the USA. Also it was a time when Statesupport for high technology projects in astronomy wasnot great since there was no awareness of the potentialfor the general economy and defense branches.

The site for the Ratan-600 radio telescope was selectedin Russia (it was the special requirement of the Govern-ment) close to the optical 6-meter telescope. It was the so-lution of the Academy of Science: integration of all groundbased facilities in one observatory. It was called the Spe-cial Astrophysical Observatory (SAO) which is until nowthe main ground-based window for Russian observers.

It is not easy to find the most effective Ratan-600 ‘slot’in radio astronomy among the collection of world facil-ities. Multi-frequency observations in the λλ1 cm–50 cmbands of strong radio sources, deep sky surveys of big fieldswith sub-mJy sensitivity at cm-wavelengths, extended skybackgrounds with sub-mK sensitivity (continuum and spec-troscopy) as well as Solar radio astronomy were the main-stay of the astrophysical program. The program committeeis overloaded with proposals in these fields.

Now it is the 50-years jubilee of the ‘BPR’ – the first1 arcmin resolution image of the Sun at 3 cm was recordedin December 1956. We suggest that this radio telescopeplayed a special role in the history of Russian radio astron-omy and may be nominated as the ‘Historical Radio Tele-scope’, as the Tatel 85-foot dish in the USA.

Early years of the Pulkovo Radio Astronomy are alsodescribed by Kaidanovskij (1985) and Balega (2006).

Acknowledgements. A.V. Temirova and N.S. Soboleva helped incollection of old photographs, and the RFBR 05–021752 grant wasused as well.

References

Alexeev, V.A., Braude, C.Ya., Brumberg, V.A., et al.: 1980, ProjectPOLIGAM, Soobshenia SAO Volumes 27, 28, 29, 30

Balega, Yu.Yu.: 2006, Special Astrophysical Observatory, 40Years, Jubilee Collection, Nizhnij Arkhyz, pp. 311–327

Bystrova, N.V., Rakhimov, I.A.: 1976, SvAL 2, 171Dravskich, A.F., Dravskich, Z.V.: 1964, Astronomich. Cirkular

282, 2Esepkina, N.A., Korolkov, D.V., Parijskij, Yu.N.: 1973, Radiote-

leskopi i Radiometri, GTTI, MoskvaFinkelstein, A.M., et al.: 2005, Proceedings of the Institute of Ap-

plied Astronomy 13, 104Ikhsanova, V.N.: 1959, in: R.N. Bracewell (ed.), Paris Symposium

on Radio Astronomy, p. 171Kaidanovskij, N.L.: 1985, Ocherki Istorii Radioastronomii v SSSR,

Kiev, pp. 141–182Kaidanovskij, N.L., Korolkov, D.V., Soboleva, N.S., Khaikin, S.E.:

1957, Dokladi Academii Nauk SSSR 112, 1012Kardashev, N.S., Parijskij, Yu.N., Umarbaeva, N.: 1973, Astrofiz.

Issledovania 5, 16Khaikin, S.E., Kaidanovskij, N.L.: 1959, Pribori i Technika Exper-

imenta 2 c, 19Khaikin, S.E., Kajdanovskij, N.L., Parijskij, Yu.N.: 1964, Proc.

XII General Assembly of IAU Comm. 40

www.an-journal.org c© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


Khaikin, S.E., Kaidanovskij, N.L., Esepkina, N.A., et al.: 1967,Izvestia GAO v Pulkove 182, 235

Khaikin, S.E., Kaidanovskij, N.L., Parijskij, Yu.N., Esepkina,N.A.: 1972, Izvestiia GAO v Pulkove 188, 3

Korolkov, D.V., Parijskij, Yu.N., Timofeeva, G.M., Khaikin, S.E.:1963, Dokladi Academii Nauk SSSR 149, 65

Parijskij, Yu.N.: 1959, Dokladi Academii Nauk SSSR 129, 1261Parijskij, Yu.N.: 1970, ThesisParijskij, Yu.N.: 1973, Astron. J. USSR 50, 453; also in SvA 16,

1048Parijskij, Yu.N., Prozorov, V.A.: 1964, Izvestiia GAO v Pulkove

23, 9

Parijskij, Yu.N., Pyatunina, T.B.: 1970, AZh 47, 1337Parijskij, Yu.N., Golnev, V.Ya., Lipovka, N.M: 1967, Izvestiia

GAO v Pulkove 24, 163Popov, A.S.: 1897, The Electrician 40, 1021Shklovskij, I.S.: 1956, Kosmicheskoe Radioizluchenie (Cosmic

Radio Waves), GITTL, MoskvaShmaonov, T.A.: 1957, Pribori i Technika Experimenta 1, 83Soboleva, N.S.: 1962, Astr. J. USSR 39, 1124Soboleva, N.S.: 1966, ThesisZkharenko, V.F., Kaidanovskij, N.L., et al.: 1963, Astr. J. USSR

40, 216


the big pulkovo radio telescope and pulkovo radio astronomy

Documents