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Modeling Results of Multibeam Radiation Patterns and Efficiency of ESMT in Cassegrain Focus in the Range of 1–3 mm

Transactions of IAA RAS, issue 65, 29–41 (2023)

Keywords: submillimeter telescope, multi-beam radiation pattern, aberration loss of efficiency, field of view, matrix mode of operation

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Abstract

New single mm/sub-mm telescopes are in high demand in Eurasia today, as is their inclusion in the mm/sub-mm VLBI. The purpose of this work is to obtain multipath radiation patterns of ESMT in the range of 2–3 mm and to estimate the aberration losses of ESMT efficiency in the range of 1–3 mm for the Cassegrain scheme without the use of tertiary optics. This will make it possible to evaluate the possibilities of using small-format arrays in the ESMT Cassegrain focus for antennal measurements and calibration observations, including instantaneous observations of most of the Moon's disk, as well as for spectral observations of extended galactic objects and active regions of the Sun. By direct integration of the aperture field, single and multibeam ESMT RP were calculated from the Cassegrain focus on a wave of 3 mm and 2 mm for a flat matrix of 9 × 9 receivers (horns), which is close to the permissible limit. By various methods, we also calculated the aberration efficiency losses of ESMT in the range of 1–3 mm for the matrix mode of operation from the secondary focus. It is shown that the most significant aberration in the focus of Cassegrain in the field of view 15' × 15' or more is the curvature of the image field (CIF). The results of modeling and calculations of RP, phase error in disclosure, and the expected aberration efficiency losses according to Ruze and Shillue in comparison with the ALMA telescope and the MMA antenna are given.

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G. A. Makoev, V. B. Khaikin. Modeling Results of Multibeam Radiation Patterns and Efficiency of ESMT in Cassegrain Focus in the Range of 1–3 mm // Transactions of IAA RAS. — 2023. — Issue 65. — P. 29–41.

@article{makoev2023,
  abstract = {New single mm/sub-mm telescopes are in high demand in Eurasia today, as is their inclusion in the mm/sub-mm VLBI. The purpose of this work is to obtain multipath radiation patterns of ESMT in the range of 2–3 mm and to estimate the aberration losses of ESMT efficiency in the range of 1–3 mm for the Cassegrain scheme without the use of tertiary optics. This will make it possible to evaluate the possibilities of using small-format arrays in the ESMT Cassegrain focus for antennal measurements and calibration observations, including instantaneous observations of most of the Moon's disk, as well as for spectral observations of extended galactic objects and active regions of the Sun. 
By direct integration of the aperture field, single and multibeam ESMT RP were calculated from the Cassegrain focus on a wave of 3 mm and 2 mm for a flat matrix of 9 × 9 receivers (horns), which is close to the permissible limit. By various methods, we also calculated the aberration efficiency losses of ESMT in the range of 1–3 mm for the matrix mode of operation from the secondary focus. It is shown that the most significant aberration in the focus of Cassegrain in the field of view 15' × 15' or more is the curvature of the image field (CIF). The results of modeling and calculations of RP, phase error in disclosure, and the expected aberration efficiency losses according to Ruze and Shillue in comparison with the ALMA telescope and the MMA antenna are given.},
  author = {G.~A. Makoev and V.~B. Khaikin},
  doi = {10.32876/ApplAstron.65.29-41},
  issue = {65},
  journal = {Transactions of IAA RAS},
  keyword = {submillimeter telescope, multi-beam radiation pattern, aberration loss of efficiency, field of view, matrix mode of operation},
  pages = {29--41},
  title = {Modeling Results of Multibeam Radiation Patterns and Efficiency of ESMT in Cassegrain Focus in the Range of 1–3 mm},
  url = {http://iaaras.ru/en/library/paper/2156/},
  year = {2023}
}

TY  - JOUR
TI  - Modeling Results of Multibeam Radiation Patterns and Efficiency of ESMT in Cassegrain Focus in the Range of 1–3 mm
AU  - Makoev, G. A.
AU  - Khaikin, V. B.
PY  - 2023
T2  - Transactions of IAA RAS
IS  - 65
SP  - 29
AB  - New single mm/sub-mm telescopes are in high demand in Eurasia today,
as is their inclusion in the mm/sub-mm VLBI. The purpose of this work
is to obtain multipath radiation patterns of ESMT in the range of 2–3
mm and to estimate the aberration losses of ESMT efficiency in the
range of 1–3 mm for the Cassegrain scheme without the use of tertiary
optics. This will make it possible to evaluate the possibilities of
using small-format arrays in the ESMT Cassegrain focus for antennal
measurements and calibration observations, including instantaneous
observations of most of the Moon's disk, as well as for spectral
observations of extended galactic objects and active regions of the
Sun.   By direct integration of the aperture field, single and
multibeam ESMT RP were calculated from the Cassegrain focus on a wave
of 3 mm and 2 mm for a flat matrix of 9 × 9 receivers (horns), which
is close to the permissible limit. By various methods, we also
calculated the aberration efficiency losses of ESMT in the range of
1–3 mm for the matrix mode of operation from the secondary focus. It
is shown that the most significant aberration in the focus of
Cassegrain in the field of view 15' × 15' or more is the curvature of
the image field (CIF). The results of modeling and calculations of
RP, phase error in disclosure, and the expected aberration efficiency
losses according to Ruze and Shillue in comparison with the ALMA
telescope and the MMA antenna are given.
DO  - 10.32876/ApplAstron.65.29-41
UR  - http://iaaras.ru/en/library/paper/2156/
ER  -