arXiv subjects

Sahana Bhattramakki

Publications and source records attributed to Sahana Bhattramakki.

3 recordsLinked to original sources

arXiv2026

GBD-DART-I : Pulsars and transient source observation between 130 MHz and 350 MHz at Gauribidanur

Gauribidanur Diamond Array Radio Telescope (GBD-DART) is a new small LPDA antenna array consisting of 64 short dipoles and associated receivers that has been custom developed and deployed at the Gauribidanur observatory (13.604 N, 77.427 E) to study bright Pulsars and Solar transients in the frequency range of 130-350 MHz. The LPDAs are arranged in a checkerboard layout, with opposite pairs combined to enable dual-polarised operation. A diamond-shaped (tilted square) array configuration was chosen to achieve high sidelobe suppression in the East-West and North-South directions. The tile measures 5.9 meters by 5.9 meters, with diagonals along both the North-South and East-West directions, each measuring about 8.4 meters. The LPDA array with one diamond-shaped tile has been fully commissioned and is operating in transit-observing mode, successfully detecting strong pulsars and solar flares over the last seven months. The present digital backend restricts the instantaneous bandwidth for observations to 16 MHz. The array operations are streamlined to facilitate remote operations. Apart from investigating Pulsar and Solar phenomena at low radio frequencies in selected sources, this work aims to provide a training platform for radio astronomy through simple-to-construct, low-cost radio telescopes. In this paper, we present details of the array, including antenna and array response studies, brief descriptions of front-end and backend instrumentation, and illustrative results from observations of both pulsars and solar flares. It will also provide brief details of future upgrade plans, particularly for the tiles and digital backend, to facilitate the observation of additional sources.

astro-ph.IM↗

arXiv2023

Progression of Digital-Receiver Architecture: From MWA to SKA1-Low,and beyond

Backed by advances in digital electronics, signal processing, computation, and storage technologies, aperture arrays, which had strongly influenced the design of telescopes in the early years of radio astronomy, have made a comeback. Amid all these developments, an international effort to design and build the world's largest radio telescope, the Square Kilometre Array (SKA), is ongoing. With its vast collecting area of 1 sq-km, the SKA is envisaged to provide unsurpassed sensitivity and leverage technological advances to implement a complex receiver to provide a large field of view through multiple beams on the sky. Many pathfinders and precursor aperture array telescopes for the SKA, operating in the frequency range of 10-300 MHz, have been constructed and operationalized to obtain valuable feedback on scientific, instrumental, and functional aspects. This review article looks explicitly into the progression of digital-receiver architecture from the Murchison Widefield Array (precursor) to the SKA1-Low. It highlights the technological advances in analog-to-digital converters (ADCs),field-programmable gate arrays (FPGAs), and central processing unit-graphics processing unit (CPU-GPU) hybrid platforms around which complex digital signal processing systems implement efficient channelizers, beamformers, and correlators. The article concludes with a preview of the design of a new generation signal processing platform based on radio frequency system-on-chip (RFSoC).

astro-ph.IM↗

arXiv2023

High-Performance Computing for SKA Transient Search: Use of FPGA based Accelerators -- a brief review

This paper presents the High-Performance computing efforts with FPGA for the accelerated pulsar/transient search for the SKA. Case studies are presented from within SKA and pathfinder telescopes highlighting future opportunities. It reviews the scenario that has shifted from offline processing of the radio telescope data to digitizing several hundreds/thousands of antenna outputs over huge bandwidths, forming several 100s of beams, and processing the data in the SKA real-time pulsar search pipelines. A brief account of the different architectures of the accelerators, primarily the new generation Field Programmable Gate Array-based accelerators, showing their critical roles to achieve high-performance computing and in handling the enormous data volume problems of the SKA is presented here. It also presents the power-performance efficiency of this emerging technology and presents potential future scenarios.

astro-ph.IM↗