Table Of ContentTECHNIQUES AND METHODS OF RADIO-ASTRONOMIC RECEPTION
TEKHNIKA I METODY RADIO-ASTRONOMICHESKOGO PRIEMA
TEXHIIKA II METO)J,bl PA,IJ,IIO-ACTPOHOlVlIIqECKOrO IIPIIEMA
The Lebedev Physics Institute Series
Editors: Academicians D. V. Skobel'tsyn and N. G. Basov
P. N. Lebedev Physics Institute, Academy of Sciences of the USSR
Recent Volumes in this Series
Volume 57 Theory of Interaction of Elementary Particles at High Energies
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Volume 60 Spectroscopy of Laser Crystals with Ionic Structure
Volume 61 Theory of Plasmas
Volume 62 Methods in Stellar Atmosphere and Interplanetary Plasma Research
Volume 63 Nuclear Reactions and Interaction of Neutrons and Matter
Volume 64 Primary Cosmic Radiation
Volume 65 Stellarators
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Volume 67 Physical Investigations in Strong Magnetic Fields
Volume 68 Radia tive Recombination in Semiconductors Crystals
Volume 69 Nuclear Reactions and Charged-Particle Accelerators
Volume 70 Group-Theoretical Methods in Physics
Volume 71 Photonuclear and Photomesic Processes
Volume 72 Physical Acoustics and Optics: Molecular Scattering of Light; Propagation of Hypersound; Metal Optics
Volume 73 Microwave--Plasma Interactions
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Volume 75 Optical Properties of Semiconductors
Volume 76 Lasers and Their Applications
Volume 77 Radio, Submillimeter, and X-Ray Telescopes
Volume 78 Research in Molecular Laser Plasmas
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Volume 82 Electronic Characteristics and Electron--Phonon Interaction in Superconductlng Metals and Alloys
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Volume 86 Superconductivity
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Volume 88 Cosmic Rays in the Stratosphere and in Near Space
Volume 89 Electrical and Optical Properties of III - IV Semiconductors
Volume 90 The Kinetics of Simple Models in the Theory of Oscillations
Volume 91 Lasers and Their Applications in Physical Research
Volume 93 Techniques and Methods of Radio-Astronomic Reception
Volume 94 Pulsed Neutron Research
Volume 96 Problems in the General Theory of Relativity and Theory of Group Representations
Volume 97 Excitons and Domain Luminescence of Semiconductors
Volume 100 Microwave Studies of Exciton Condensation in Germanium
In preparation:
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Proceedings (Trudy) of the P. N. Lebedev Physics Institute
Volume 93
Techniques and Methods
of Radio-Astronomic Receptie) il
Edited by
N. c;. Basov
P. N. Lebedev Physics Institute
Academy of Sciences ofthe USSR
Moscow, USSR
Translated from Russian
SPRINGER SCIENCE+BUSINESS MEDIA, LLC
Library of Congress Cataloging in Publication Data
Main entry under title:
Techniques and methods of radio-astronomic reception.
(Proceedings (Trudy) of the P. N. Lebedev Physics Institute, Academy of Sciences of the
USSR; v. 93)
Translation of Tekhnika i metody radio-astronomicheskogo priema.
lncludes index(es)
1. Radio astronomy--Addresses, essays, lectures. 2. Radio telescope-Addresses, essays,
lectures. 1. .Basov, Nikolai Gennadievich, 1922- II. Series: Akademiia nauk SSSR.
Fizicheskii institut. Proceedings; v. 93.
QC1.A4114 voi. 93 [QB478.5] 530'.08s [522 .682]
78-26720
The original Russian text was published by Nauka Press in Moscow in 1977 for the Academy
of Sciences of the USSR as Volume 93 of the Proceedings of the P. N. Lebedev Physics
Institute. This translation is published under an agreement with the Copyright Agency of
the USSR (VA AP).
ISBN 978-3-642-98584-3 ISBN 978-1-4684-1638-1 (eBook)
DOI 10.1007/978-1-4684-1638-1
© 1979 Springer Science+Business Media New York
Originally published by Consultants Bureau, New York in 1979
A Division of Plenum Publishing Corporation
227 West 17th Street, New York, N.Y. 10011
AII righ ts reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted,
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recording, or otherwise, without written permission from the Publisher
CONTENTS
Automation of Radio-Astronomic Investigations Using the RT-22
Radio Telescope with an Electronic Computer ••••.•••••••••. 1
A. V. Kutsenko, B. A. Polos'yants, Yu. M. Polubesova,
and R. L. Sorochenko
The Problem of Matching a Noise Generator .••• 19
1. A. Alekseev and V. N. Brezgunov
Some Structural Designs of the Main Subassemblies of Fully Inclinable and
Rotatable Parabolic Radio-Telescope Antennas . . • • • . • • • • • • • • • • • • • . • • 23
P. D. Kalachev, 1. A. Emel'yanov, V. P. Nazarov, V. L. Shubeko,
and V. B. Khavaev
Precision System for Guiding the RT-22 Radio Telescope of the Physics
Institute of the Academy of Sciences of the USSR. • • • • • • • • • • • • • • • • • • • • 47
V. A. Vvedenskii, P. D. Kalachev, A. D. Kuz'min, Yu. N. Semenov,
and R. L. Sorochenko
Analysis of the Components of Aerodynamic Moments in Parabolic Antennas 53
V. E. D'yachkov, S. L. Myslivets, and V. P. Nazarov
A Method for Determining the Cost of Fabrication of a Fully Rotatable and
Inclinable Radio Telescope ••••••••••• . . • • • . • • . • • • • • • • • • . • . • • • 63
P. D. Kalachev, A. V. Samotsetov, and E. A. Tret'yakov
Automation of the Processing of Pulsar Observations .••••••••••• 75
B. V. Vyzhlov, V. V. Ivanova, V. A. Izvekova, A. D. Kuz'min,
Yu. P. Kuz'min, V. M. Malofeev, Yu. M. Popov, N. S. Solomin,
T. V. Shabonova, and Yu. P. Shitov
Progress in Radio-Astronomic Investigations of the Solar-Wind Velocity. • • • • • • • • 85
N. A. Lotova and r. V. Chashei
Influence of the Doppler Effect in Measurements of the Periods of Pulsars 125
T. V. Shabanova
Sonic Direction Finding in the Presence of Strong Acoustic Interference 133
V. r. Veksler and E. L. Feinberg
v
AUTOMATION OF RADIO-ASTRONOMIC INVESTIGATIONS
USING THE RT-22 RADIO TELESCOPE WITH AN
ELECTRONIC COMPUTER
A. V. Kutsenko, B. A. Polos'yants, Yu. M. Polubesova,
and R. L. Sorochenko
The basic requirements of a system for automating radio-astronomic investigations with the RT -22 radio
telescope are formulated, and its functional arrangement is described. The reasons are given for the se-
lection of the system's programming and configuration, and the principal operational algorithms are pre-
sented.
The 22-meter R T-22 radio telescope of the P. N. Lebedev Institute of Physics [1] has
continued, up to the present time, to be one of the largest radio telescopes in the world that
works in the millimeter wave band. This radio telescope is equipped with highly sensitive ap-
paratus that utilizes quantum paramagnetic amplifiers (masers). The current level of radio-
astronomic research requires that the instrument system of a radio telescope include an elec-
tronic computer as an essential component, in order to ensure the control of all the processes
of observation. Below is described the design for the total automation of radio-astronomic ob-
servations using the R T-22 radio-telescope with an M-6000 electronic computer.
1. The Requirements of the System and Its
Functional Arrangement
The system for automating the R T-22 involves the following operations: (1) observation
programming in accordance with input data; (2) aiming and guidance of the radio telescope in
accordance with the program; (3) multichannel collection of information and its storage and
preliminary processing; (4) programmed control of the radio-astronomic receiving apparatus,
and calibration and verification of the necessary parameters; (5) recording of data on the radio
telescope's position and on the signals being received, and their output in the form of quick
information for observation and in a form permitting further proceSSing with large electronic
computers or with the radio telescope's own computer during time not used for observations.
The operation of the entire system must proceed on a real time scale with the precise
correlation needed for astronomic measurements. A diagram of the automation system for
radio-astronomic observations, constructed on the basis of the above-listed requirements, is
presented in Fig. 1.
1.1. Aiming and Guidance of the Radio Telescope
The aiming of the radio telescope at an assigned spot on the celestial sphere is one of
the basic technical problems in radio-astronomic observations. With the RT-22's directional-
1
2 A. v. KUTSENKO ET AL.
Input of results of ob-
Input of program Input of
servations for sub-
and initial data astronomical
sequent processing in
for observations time
free time
I
~ 1 !
Control of the
Aiming and guidance Electronic radio-astronomic
of radio telescope computer receiving ap-
paratus
I I
J ~
Output of quick in- Output of data for
formation in visual subsequent computer
form processing
Fig. 1. Diagram of the automation of radio-astronomic observations with
the R T-22 radio telescope.
diagram width of 1.9 minutes of arc (at the shortest operating wavelength of 8 mm), the re-
quired spatial aiming accuracy should be not worse than 10"-15". A generalized diagram of
the radio telescope's guidance [2] along one coordinate is presented in Fig. 2. The computer,
operating on a real time scale provided by an outside timer, computes in steps of 0.5, with
coordinates and velocity along both axes. With the prescribed overall aiming error of 10" to
15", the required accuracy for computing the coordinates should be ~1", which corresponds
to 21 binary orders in azimuth and 19 binary orders in angle of elevation. The true position
of the radio telescope is determined by 18-order angle-code (angle-digital) data units installed
on the radio telescope's axes. The discrimination of the angular-mismatch or angular-error
signals and the display of the necessary quantities are done by the electronic computer.
Angle-data
1.---------------------------------1 trans-
mitter
computer
Recording of
radio tele- Mismatch or
scope's true Error signal Automatic track-
and calculated '------'-"-=-:=:.;;.;..::.-1 ing system of the ~====~
positions RT-22
Fig. 2. Generalized diagram of the RT-22's guidance by the elec-
tronic computer, along one coordinate.
A. V. KUTSENKO ET AL. 3
Depending on the program of scientific observations, the radio telescope's guidance sys-
tem must secure:
1. The aiming of the radio telescope at the necessary point on the celestial sphere.
2. The tracking of the assigned point, which moves across the celestial sphere in ac-
cordance with the laws of motion of the stars, sun, solar-system planets, and moon.
It is possible to follow two basic procedures in this program: (a) tracking by the
aiming-withdrawal method, in which the radial telescope observes the source and then
withdraws to a reference point, and (b) tracking, by the aiming- aiming method, in which
the radio telescope, operating with a symmetrical diagram modulation, observes the
source alternately in one or the other possible directions of reception [3].
3. The passage of the radio telescope's directional diagram through the selected point
with a given velocity, that is, a scanning regime.
The aiming should be done both by the geometric axis of the radio telescope and by an
axis offset from the geometric one through an angle of lOin both coordinates.
The Radio Telescope's Guidance Algorithm. For computation of the radio
telescope's position at the time of observations by the "aiming" and "tracking" programs, the
initial data are: (1) the right ascension O! of the point being observed; (2) corrections to the
right ascensions for planets, sun, and moon, daily and hourly accordingly, D.O!m (mean); (3)
declination 0; (4) corrections to the declinations for planets, sun, and moon, D.0 m ; (5) uni-
versal stellar time So; (6) collimation correction of the radio telescope in azimuth, D.A e; (7)
collimation correction of the radio telescope in zenith distance, D.Z e.
At the time of observations by the aiming-withdrawal program, to the initial data are
added: (8) the coordinates of a reference point, 0!2' 02; (9) the tracking times for the experi-
mental and reference points, T1 and T2.
At the time of observations by the aiming-aiming method, to the initial data are added:
(8) the difference between the two directions of reception in azimuthal coordinates (with arbi-
trary direction of the radio telescope to the zenith), D.A d , D.Z d ; (9) the duration of observations
in each of the directions of reception, T1 and T2.
At the time of observations by the scanning program, the scanning parameters are also
initial data. Four kinds of scanning are possible.
Scanning along the Right Ascension o!. Specified are: (1) right-ascension scanning
range D.O!lim; (2) scanning rate a; (3) declination scan interval D.0 se ; (4) declination scan
limit D.0lim'
Scanning along the Declination 0. Specified are: (1) declination scanning range D.0lim ;
(2) scanning rate 6; (3) right-ascension scan interval D.O!se; (4) right-ascension scan limit
D.O!lim·
Scanning. along the Azimuth A. Specified are: (1) azimuth scanning range ~Alim; (2)
scanning rate A; (3) zenith scan interval D. Z se ; (4) zenith scan limit D. Z lim'
Scanning along the Zenith Distance Z. Specified are: (1) zenith-distance scanning range
D. Z; (2) scanning rate Z; (3) azimuth scan interval D.A se; (4) scan limit D.AUm '
In addition to the above-mentioned initial data, the various programs for the computer
solution of the guidance problems involve the following:
Absolute constants: (1) the radio telescope's geographic latitude cp; (2) the radio tele-
scope's geographic longitude '\; (3) the time-zone number N; (4) the refraction constant
(see below);
4 A. V. KUTSENKO ET AL.
Input of initial data
~
Input of time
l
Mt: computation of tp
and 6
!
Is there scanning in Ma
equatorial Scanning along
coordinates? equatorial coordin-
ates
ex=o ex -# 0, i; "'" 0
Ii =0 ~
r--- Smcuatnhnailn gco aolrodnign atzeis-
M2 ..-
Computation of Z, A, i,A
Calculation Computation of refraction
of correction
for collima- 1- Computation of parallax
tion
I . Computation of
A' = A + ~Ac
Z' = Z - r - P + ~Zc
Correction Yes
unit I- Is correction needed?
I J No
r- Rough aim ~LI I Z 1<2° ?
I Stop +
Is there scanning in
azimuthal
coordinates?
IA oF 0; i *- 0
~ = 0 1
z=o
i
I
nse icnetsesraproyla?t ion Yes M4, M5:
interpolation
No and scanning
~
Introduction of Ztrue'
A true
-+
Ms
I ~z I >2°, I ~ A I >2° Computation of ~Z. ~A
Verification of the
procedure
10' I t.Az 1I <2° 1
1I t.Az 1< 10'
Output of b.A, b. Z. Output ~f b.A, b.Z,
max A, and max Z A, and Z to the
to the power system power system
t
Fig. 3. Block diagram of the radio telescope's guidance algorithm.
