An Active Antenna Subarray for the Low-Frequency Radio Telescope GURT—Part II: Numerical Analysis and Experiment

2019 ◽  
Vol 67 (12) ◽  
pp. 7312-7319 ◽  
Author(s):  
Peter L. Tokarsky ◽  
Alexander A. Konovalenko ◽  
Serge N. Yerin ◽  
Igor N. Bubnov
Keyword(s):  
Numerical Analysis ◽  
Radio Telescope ◽  
Low Frequency ◽  
Active Antenna

Sensitivity of an Active Antenna Array Element for the Low-Frequency Radio Telescope GURT

2017 ◽  
Vol 65 (9) ◽  
pp. 4636-4644 ◽  
Author(s):  
Peter L. Tokarsky ◽  
Alexander A. Konovalenko ◽  
Serge N. Yerin
Keyword(s):  
Antenna Array ◽  
Radio Telescope ◽  
Low Frequency ◽  
Array Element ◽  
Active Antenna

An Active Antenna Subarray for the Low-Frequency Radio Telescope GURT—Part I: Design and Theoretical Model

2019 ◽  
Vol 67 (12) ◽  
pp. 7304-7311 ◽  
Author(s):  
Peter L. Tokarsky ◽  
Alexander A. Konovalenko ◽  
Serge N. Yerin ◽  
Igor N. Bubnov
Keyword(s):  
Theoretical Model ◽  
Radio Telescope ◽  
Low Frequency ◽  
Active Antenna

Thirty-Element Active Antenna Array as a Prototype of a Huge Low-Frequency Radio Telescope

2003 ◽  
Vol 16 (3) ◽  
pp. 149-164 ◽  
Author(s):  
Alexander Alexandrovich Konovalenko ◽  
Igor Savelievich Falkovich ◽  
Nikolay Nikolaevich Kalinichenko ◽  
Alexander Alexandrovich Gridin ◽  
Igor Nikolaevich Bubnov ◽  
...  
Keyword(s):  
Antenna Array ◽  
Radio Telescope ◽  
Low Frequency ◽  
Active Antenna

Impact of Ground Parameters on Performances of an Active Phased Array Element of the Low-Frequency Radio Telescope GURT

2020 ◽  
Vol 09 (04) ◽  
pp. 2050015
Author(s):  
Peter Tokarsky ◽  
Alexander Konovalenko ◽  
Mykola Kalinichenko ◽  
Serge Yerin
Keyword(s):  
Radio Telescope ◽  
Phased Array ◽  
Extreme Values ◽  
Low Frequency ◽  
Numerical Estimation ◽  
Active Antenna ◽  
Phased Array Antenna ◽  
Absorption Area ◽  
Ground Conditions ◽  
The Impact

This paper presents the technique of numerical estimation of ground parameters impact on the performances of an active antenna used as an element of a phased array antenna of a modern low-frequency radio telescope. Three ground conditions were considered, two of them wet and dry, which correspond to the extreme values of seasonal deviations of its parameters, as well as its median state (“normal ground”). The results of computer simulation are given for the active antenna of the GURT radio telescope with a ground screen in the form of a square wire grid of [Formula: see text][Formula: see text]m and without it. It is shown that the addition of the ground screen markedly reduces the influence of the ground conditions on some parameters of the antenna, in particular, the dipole impedance and radiation efficiency. At the same time, the ground screen does not protect the most important antenna parameters for radio astronomy, such as sensitivity and absorption area, from the impact of the ground conditions changes. Variations of these parameters for an active antenna with a screen remain approximately the same as without it.

scholarly journals First Radio Astronomy Examination of the Low-Frequency Broadband Active Antenna Subarray

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
A. A. Stanislavsky ◽  
I. N. Bubnov ◽  
A. A. Konovalenko ◽  
A. A. Gridin ◽  
V. V. Shevchenko ◽  
...  
Keyword(s):  
Remote Control ◽  
Antenna Array ◽  
Radio Telescope ◽  
Personal Computer ◽  
Radio Astronomy ◽  
Low Frequency ◽  
Delay Lines ◽  
Online Interaction ◽  
Active Antenna ◽  
Parallel Data

We present the 25-element active antenna array and its remote control in the framework of the GURT project, the Ukrainian Radio Telescope of a new age. To implement beamforming, the array is phased with the help of discrete cable delay lines in analog manner. The remote control of the array is carried out through the paired encoder and decoder that can transmit parallel data about antenna codes serially. The microcontroller provides the online interaction between personal computer and beamformers with the help of the encoder-decoder system through wires or wireless. The antenna pattern has been measured by radio astronomy methods.

30-element active antenna array as a prototype of a huge low-frequency radio telescope

2004 ◽  
Author(s):  
I.S. Falkovich ◽  
A.A. Konovalenko ◽  
N.N. Kalinichenko ◽  
A.A. Gridin ◽  
A. Lecacheux ◽  
...  
Keyword(s):  
Antenna Array ◽  
Radio Telescope ◽  
Low Frequency ◽  
Active Antenna

scholarly journals A Low frequency Southern Sky Survey Using the Mauritius Radio Telescope

2002 ◽  
Vol 199 ◽  
pp. 25-31
Author(s):  
N. Udaya Shankar
Keyword(s):  
Radio Telescope ◽  
Low Frequency ◽  
Fourier Synthesis ◽  
North East ◽  
The North ◽  
Sky Survey ◽  
Correlation Receiver ◽  
Complex Correlation ◽  
Right Ascension ◽  
East West

The Mauritius Radio Telescope (MRT) is a Fourier synthesis instrument which has been built to fill the gap in the availability of deep sky surveys at low radio frequencies in the southern hemisphere. It is situated in the north-east of Mauritius at a southern latitude of 20°.14 and an eastern longitude of 57°.73. The aim of the survey with the MRT is to contribute to the database of southern sky sources in the declination range −70° ≤ δ ≤ −10°, covering the entire 24 hours of right ascension, with a resolution of 4' × 4'.6sec(δ + 20.14°) and a point source sensitivity of 200 mJy (3σ level) at 151.5 MHz.MRT is a T-shaped non-coplanar array consisting of a 2048 m long East-West arm and a 880 m long South arm. In the East-West arm 1024 fixed helices are arranged in 32 groups and in the South arm 16 trolleys, with four helices on each, which move on a rail are used. A 512 channel, 2-bit 3-level complex correlation receiver is used to measure the visibility function. At least 60 days of observing are required for obtaining the visibilities up to the 880 m spacing. The calibrated visibilities are transformed taking care of the non-coplanarity of the array to produce an image of the area of the sky under observation.This paper will describe the telescope, the observations carried out so far, a few interesting aspects of imaging with this non-coplanar array and present results of a low resolution survey (13' × 18') covering roughly 12 hours of right ascension, and also present an image with a resolution of 4' × 4'.6sec(δ + 20.14°) made using the telescope.

scholarly journals Low frequency radio counterparts of HESS J1731−347 a.k.a SNR G353.6−0.7

2017 ◽  
Vol 12 (S331) ◽  
pp. 201-205
Author(s):  
A. J. Nayana ◽  
Poonam Chandra
Keyword(s):  
Radio Emission ◽  
Radio Telescope ◽  
Supernova Remnants ◽  
Low Frequency ◽  
High Energy ◽  
Spectral Indices ◽  
Thermal Radio Emission ◽  
Very High Energy ◽  
Γ Rays ◽  
Very High

AbstractHESS J1731−347 a.k.a. SNR G353.6−0.7 is one of the five known very high energy (VHE, Energy > 0.1 TeV) shell-type supernova remnants. We carried out Giant Metrewave Radio Telescope (GMRT) observations of this TeV SNR in 1390, 610 and 325 MHz bands. We detected the 325 and 610 MHz radio counterparts of the SNR G353.6−0.7 (Nayana et al. 2017). We also determined the spectral indices of individual filaments and our values are consistent with the non-thermal radio emission. We compared the radio morphology with that of VHE emission. The peak in radio emission corresponds to the faintest feature in the VHE emission. We explain this anti-correlated emission in a possible leptonic origin of the VHE γ-rays.

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