http://hdl.handle.net/2289/5122 Wed, 08 Apr 2026 10:40:13 GMT 2026-04-08T10:40:13Z http://hdl.handle.net/2289/8429 Title: The Indian Pulsar Timing Array data release 2: I. Dataset and timing analysis Authors: Rana, Prerna; Tarafdar, Pratik; Nobleson, K; Dwivedi, Churchil; Joshi, Bhal Chandra; Deb, Debabrata; Mondal, Sushovan; Krishnakumar, M A; Shukla, Adya; Singha, Jaikhomba; Grover, Himanshu; Tahbildar, Hemanga; Susobhanan, Abhimanyu; Surnis, Mayuresh; Desai, Shantanu; Batra, Neelam Dhanda; Srivastava, Aman; Bharambe, Vinay; Jose, Jibin; Vyasraj, Vaishnavi; Jacob, Shebin Jose; Amarnath; Singh, Manpreet; Zuraiq, Zenia; Sengupta, Sarbartha; Ogi, Toki; Kumar, Dhruv; Jagadeesh, S; Kareem, Fazal; Maity, Deep; Rai, Kaustubh; Vara, Kunjal; Chowdhury, Shaswata; Kato, Ryo; Arumugam, Swetha; Mamidipaka, Pragna; Pandian, B Arul; Shaji, Kavya; Prabu, T; Arumugam, Paramasivan; Bagchi, Manjari; Chakraborty, Manoneeta; Gopakumar, Achamveedu; Gupta, Yashwant; Maan, Yogesh; Paladi, Avinash Kumar; Takahashi, Keitaro Description: Restricted Access Thu, 10 Jul 2025 00:00:00 GMT http://hdl.handle.net/2289/8429 2025-07-10T00:00:00Z http://hdl.handle.net/2289/8408 Title: An SBC-based controller and processor for the laboratory model of PRATUSH digital receiver Authors: Srivani, K S; Girish, B S; Rao, Mayuri S; Singh, Saurabh; Dash, Adarsh Kumar; Narendra, S; Agrawal, Yash; Keerthipriya, S; Somashekar, R; Madhavi, S; Rajan, Jacob; Shankar, Udaya N; Seetha, S Abstract: Probing ReionizATion of the Universe using Signal from Hydrogen (PRATUSH) is a proposed space-based radiometer that aims to detect the sky-averaged 21-cm signal from Cosmic Dawn – a crucial phase in the cosmic evolution of the Universe. PRATUSH will operate in the frequency range of 55-110 MHz. PRATUSH will conduct observations in low earth orbit in its first phase, followed by lunar orbit in the second phase. Digital correlation spectrometer is an integral subsystem of PRATUSH radiometer, enabling phase switching, digitization and generation of sky spectrum. The digital correlation spectrometer for PRATUSH laboratory model features 10-bit analog-to-digital converters (ADCs) and a Virtex-6 Field Programmable Gate Array (FPGA). A Raspberry Pi 4 Model B-based single-board computer (SBC) serves as the master controller, real-time processor and data recorder, to minimize the power, mass and volume requirement of the laboratory model. This paper presents the implementation of the PRATUSH laboratory model digital receiver, challenges arising from the use of an SBC in place of a conventional computer, and demonstrates the performance of the spectrometer when integrated with the PRATUSH laboratory model analog receiver. Description: Restricted Access Mon, 16 Jun 2025 00:00:00 GMT http://hdl.handle.net/2289/8408 2025-06-16T00:00:00Z http://hdl.handle.net/2289/8405 Title: Frequency-independent antennas for low-frequency radio telescope Authors: Raghunathan, Agaram; Kavitha, K; Keerthipriya, Sathish; Arasi, S; Nagaraja, H N; Sethi, Shiv Abstract: Exploring the universe at low frequencies for sensitive and broadband polarization studies of a range of radio sources is expected to open up a new dimension to radio astronomical observation. Building a low-frequency radio telescope (LFRT) to operate over the frequency band of 30–360 MHz with a wide field-of-view (FOV) capability and an instantaneous bandwidth of 300 MHz is considered most rewarding for observing the low-frequency universe. For this telescope, two reflector-based dipole antennas have been designed with 1:3 bandwidth to operate in the frequency bands of 30–90 MHz and 120–360 MHz to simultaneously cover the frequency band of 30–360 MHz. They are planar, profiled, and tilted to achieve larger bandwidth and frequency-independent radiation and impedance characteristics. The frequency-independent characteristic is expected to ease the calibration of the antenna bandpass response. The antennas have i) a moderate reflection coefficient of less than −4 dB over their operating bands with a smooth spectral response and ii) frequency-independent E-plane radiation patterns having a maximum dispersion in their half-power beamwidths of less than 10% across their operating bands. The structural parameters of the antennas have been optimized using electromagnetic modeling, and the designs have been validated by constructing prototypes. Description: Open Access from Indian Academy of Sciences Sat, 17 May 2025 00:00:00 GMT http://hdl.handle.net/2289/8405 2025-05-17T00:00:00Z http://hdl.handle.net/2289/8397 Title: Innovative web tool for remote data acquisition and analysis: Customized for SKA low frequency beamforming test bed LPDA array at Gauribidanur Radio Observatory Authors: Likhit, Anumanchi Agastya Sai Ram; Naveen, Katta; Pandian, B Arul; Abhishek, R; Prabu, T Description: Open Access from Indian Academy of Sciences Sat, 10 May 2025 00:00:00 GMT http://hdl.handle.net/2289/8397 2025-05-10T00:00:00Z