Mr. Pravinkumar A. Chordia Profile

Pravinkumar A. Chordia

Scientific Officer at Inter-Univ Ctr for Astronomy and Astrophysics

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Publications (14)

Proceedings Article | 13 December 2020 Poster + Presentation + Paper

WALOP-South: A wide-field one-shot linear optical polarimeter for PASIPHAE survey

Siddharth Maharana, John Kypriotakis, A. Ramaprakash, Chaitanya Rajarshi, Stephen Potter, Pravin Khodade, Pravin Chordia, Bhushan Joshi, Georgia Panopoulou, Konstantinos Tassis, Anthony C. Readhead, Timothy Pearson, Ingunn Wehus, Hans Kristian Eriksen, Dmitry Blinov, Vasiliki Pavlidou, Raphail Skalidis, Vincent Pelgrims, Ramya Anche, Shrish Mishra, Tuhin Ghosh, Eirik Gjerløw, Nikolaos Mandarakas

Proceedings Volume 11447, 114475E (2020) https://doi.org/10.1117/12.2554396

KEYWORDS: Polarimetry, Polarization, Telescopes, Stars, Astronomy, Optical filters, Photometry, Prisms, Vignetting, Optomechanical design

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SPIE Journal Paper | 25 July 2019 Open Access

Design and development of an adaptive optics system in visible and near-infrared for Inter-University Centre for Astronomy and Astrophysics 2-meter telescope

Jyotirmay Paul, Hillol Kanti Das, Anamparambu Ramaprakash, Mahesh Burse, Pravinkumar Chordia, Kalpesh Chillal, Gaurav Datir, Bhushan Joshi, Pravin Khodade, Abhay Kohok, Vilas Mestry, Sujit Punnadi, Chaitanya Rajarshi, Chikku Shekhar

JATIS, Vol. 5, Issue 03, 039002, (July 2019) https://doi.org/10.1117/12.10.1117/1.JATIS.5.3.039002

KEYWORDS: Adaptive optics, Telescopes, Prisms, Cameras, Projection systems, Ultraviolet radiation, Mirrors, Infrared cameras, Zemax, Atmospheric modeling

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Proceedings Article | 11 July 2018 Paper

Design and development of IR camera

Jyotirmay Paul, A. Ramaprakash, Hillol Das, Mahesh Burse, Pravin Chordia, Pravin Khodade, Abhay Kohok, Deepa Modi , Sujit Punnadi, Chaitanya Rajarshi, Vilas Mestry

Proceedings Volume 10703, 1070368 (2018) https://doi.org/10.1117/12.2311457

KEYWORDS: Infrared cameras, Cameras, Sensors, Optical filters, Adaptive optics, Infrared sensors, Telescopes, Infrared telescopes, Infrared radiation

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SPIE Journal Paper | 11 July 2018

Noise characterization of IUCAA digital sampling array controller

Sabyasachi Chattopadhyay, A. N. Ramaprakash, Bhushan Joshi, Pravinkumar Chordia, Mahesh Burse, Kalpesh Chillal, Sakya Sinha, Sujit Punnadi, Ketan Rikame, Sungwook Hong, Dhruv Paranjpye, Haeun Chung, Changbom Park, Amitesh Omar

JATIS, Vol. 4, Issue 03, 036002, (July 2018) https://doi.org/10.1117/12.10.1117/1.JATIS.4.3.036002

KEYWORDS: Interference (communication), Charge-coupled devices, Electrons, Analog electronics, Clocks, Amplifiers, Power supplies, Sensors, Field programmable gate arrays, Statistical modeling

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The IUCAA digital sampling array controller (IDSAC) is a flexible and generic yet powerful CCD controller that can handle a wide range of scientific detectors. Based on an easily scalable modular backplane architecture consisting of single board controllers (SBC), IDSAC can control large detector arrays and mosaics. Each of the SBCs offers the full functionality required to control a CCD independently. The SBCs can be cold swapped without the need to reconfigure them. IDSAC is also available in a backplane-less architecture. Each SBC can handle data from up to four video channels with or without dummy outputs at speeds up to 500-kilo pixels per second (kPPS) per channel with a resolution of 16 bits. Communication with a Linux-based host computer is through a USB3.0 interface, with the option of using copper or optical fibers. A field programmable gate array (FPGA) is used as the master controller in each SBC, which allows great flexibility in optimizing performance by adjusting gain, timing signals, bias levels, etc., using user-editable configuration files without altering the circuit topology. Elimination of thermal kTC noise is achieved via digital correlated double sampling (DCDS). The number of digital samples per pixel (for both reset and signal levels) is user configurable. We present the results of noise performance characterization of IDSAC through simulation, theoretical modeling, and actual measurements. The contribution of different types of noise sources is modeled using a tool to predict noise of a generic DCDS signal chain analytically. The analytical model predicts the net input referenced noise of the signal chain to be 5 electrons for 200-k pixels/s per channel readout rate with three samples per pixel. Using a cryogenic test setup in the lab, the noise is measured to be 5.4 e (24.3 μV), for the same readout configuration. With a better-optimized configuration of 500-kPPS readout rate, the measured noise is down to 3.8 electrons RMS (17 μV), with three samples per interval.

Proceedings Article | 9 July 2018 Paper

DOTIFS: fore-optics and calibration unit design

Haeun Chung, A. Ramaprakash, Pravin Khodade, Chaitanya Rajarshi, Sabyasachi Chattopadhyay, Pravin Chordia, Amitesh Omar, Changbom Park

Proceedings Volume 10702, 107027U (2018) https://doi.org/10.1117/12.2312394

KEYWORDS: Calibration, Telescopes, Lamps, Mirrors, Integrating spheres, Spectrographs, Lenses, Light, Optical instrument design, Optomechanical design

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Proceedings Article | 8 July 2018 Paper

DOTIFS: spectrograph optical and opto-mechanical design

Haeun Chung, A. N. Ramaprakash, Pravin Khodade, Chaitanya Rajarshi, Sabyasachi Chattopadhyay, Pravin Chordia, Vishal Joshi, Sungwook Hong, Amitesh Omar, Swara Ravindranath, Yong-Sun Park, Changbom Park, Deepa Modi

Proceedings Volume 10702, 107027A (2018) https://doi.org/10.1117/12.2311594

KEYWORDS: Spectrographs, Cameras, Charge-coupled devices, Optical design, Collimators, Optical filters, Spectral resolution, Tolerancing, Optomechanical design, Optical fibers, Thermal analysis

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Proceedings Article | 6 July 2018 Paper

Design and results for the SAAO wide-field nasmyth camera

Pieter Swanevelder, Dave Carter, James O'Connor, Hannah Worters, Amanda Sickafoose, Willie Koorts, Briehan Lombaard, Egan Loubser, Keegan Titus, Carel van Gend, Craig Sass, Hitesh Gajjar, A. N. Ramaprakash, Pravin Chordia, Mahesh Burse, Sujit Punnadi, Bhushan Joshi, Sakya Sinha, Michael Rust

Proceedings Volume 10702, 107022K (2018) https://doi.org/10.1117/12.2312540

KEYWORDS: Camera shutters, Charge-coupled devices, Cameras, Telescopes, Astronomy

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Proceedings Article | 19 August 2016 Paper

First results and future plans for the Canarias Infrared Camera Experiment (CIRCE) for the Gran Telescopio Canarias

Alan Garner, Stephen Eikenberry, Miguel Charcos, Michelle Edwards, Nestor Lasso-Cabrera, Richard Stelter, Antonio Marin-Franch, S. Nicholas Raines, Kendall Ackley, John Bennett, Javier Cenarro , Brian Chinn, Veronica Donoso, Raymond Frommeyer, Jeff Julian, Paola Miller, Frank Varosi, Claudia Vega, Sujit Punnadi, Pravinkumar Chordia, Héctor de Paz Martín, María Martín Calero, Riccardo Scarpa, Sergio Fernandez Acosta, William Miguel Hernández Sánchez, Benjamin Siegel, Himar Viera Martín, Agustín Nuñez, Álvaro Tejero, César Cabrera Rodríguez, Jordi Molgó Sendra, Luis A. Rodríguez García, Manuel Huertas Lopez, Raul Dominguez, Antonio Cabrera-Lavers, Stefan Geier, Peter Pessev, Ata Sarajedini, A. J. Castro-Tirado, Kevin Hanna, Michael Herlevich, Scott Mullin, Charles Murphey, Christopher Packham, Craig Warner, Anamparambu Ramaprakash, Mahesh Burse, Andreas Gerarts, Francisco Francisco Pérez, José Rodríguez Losada, Carlos E. Martín González, J. Esteban Rodriguez, J. Israel Fernádez Cáceres, Tim Gaggstatter, Yigit Dallilar

Proceedings Volume 9908, 99084Q (2016) https://doi.org/10.1117/12.2232672

KEYWORDS: Infrared cameras, Polarimetry, Astronomy, X-rays, Stars, Spectroscopy, Spectroscopes, Sensors, Galactic astronomy, Binary data

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Proceedings Article | 27 July 2016 Paper

ISDEC-2 and ISDEC-3 controllers for HAWAII detectors

Sakya Sinha, Rupali Bharti, Abhay Kohok, Mahesh Burse, A. Ramaprakash, Pravinkumar Chordia, Sujit Punnadi, Kalpesh Chillal, Vilas Mestri

Proceedings Volume 9915, 991526 (2016) https://doi.org/10.1117/12.2232510

KEYWORDS: Sensors, Electronics, Astronomy, Observatories, Telescopes, Field programmable gate arrays, Interfaces, Clocks, Control systems, Analog electronics

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Proceedings Article | 27 July 2016 Paper

IDSAC-IUCAA digital sampler array controller

Sabyasachi Chattopadhyay, A. Ramaprakash, Mahesh Burse, Bhushan Joshi, Kalpesh Chillal, Pravin Chordia

Proceedings Volume 9915, 991524 (2016) https://doi.org/10.1117/12.2232477

KEYWORDS: Charge-coupled devices, Video processing, Cadmium sulfide, Video, Analog electronics, Interference (communication), Clocks, Sensors, Power supplies, Signal to noise ratio

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In order to run the large format detector arrays and mosaics that are required by most astronomical instruments, readout electronic controllers are required which can process multiple CCD outputs simultaneously at high speeds and low noise levels. These CCD controllers need to be modular and configurable, should be able to run multiple detector types to cater to a wide variety of requirements. IUCAA Digital Sampler Array Controller (IDSAC), is a generic CCD Controller based on a fully scalable architecture which is adequately flexible and powerful enough to control a wide variety of detectors used in ground based astronomy. The controller has a modular backplane architecture that consists of Single Board Controller Cards (SBCs) and can control up to 5 CCDs (mosaic or independent). Each Single Board Controller (SBC) has all the resources to a run Single large format CCD having up to four outputs. All SBCs are identical and are easily interchangeable without needing any reconfiguration. A four channel video processor on each SBC can process up to four output CCDs with or without dummy outputs at 0.5 Megapixels/Sec/Channel with 16 bit resolution. Each SBC has a USB 2.0 interface which can be connected to a host computer via optional USB to Fibre converters. The SBC uses a reconfigurable hardware (FPGA) as a Master Controller. IDSAC offers Digital Correlated Double Sampling (DCDS) to eliminate thermal kTC noise. CDS performed in Digital domain (DCDS) has several advantages over its analog counterpart, such as - less electronics, faster readout and easier post processing. It is also flexible with sampling rate and pixel throughput while maintaining the core circuit topology intact. Noise characterization of the IDSAC CDS signal chain has been performed by analytical modelling and practical measurements. Various types of noise such as white, pink, power supply, bias etc. has been considered while creating an analytical noise model tool to predict noise of a controller system like IDSAC. Several tests are performed to measure the actual noise of IDSAC. The theoretical calculation matches very well with practical measurements within 10% accuracy.

Proceedings Article | 27 July 2016 Paper

Evaluating noise performance of the IUCAA sidecar drive electronics controller (ISDEC) based system for TMT on-instrument wavefront sensing (OIWFS) application

Mahesh Burse, Swapnil Prabhudesai, Sujit Punnadi, Sabyasachi Chattopadhyay, Pravin Chordia, Abhay Kohok, Sakya Sinha, A. Ramaprakash

Proceedings Volume 9915, 991520 (2016) https://doi.org/10.1117/12.2232265

KEYWORDS: Sensors, Wavefront sensors, Control systems, Analog electronics, Multiplexers, Stars, Field programmable gate arrays, Power supplies, Electrons, Interfaces

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Proceedings Article | 18 July 2016 Paper

The Solar Ultraviolet Imaging Telescope onboard Aditya-L1

Aafaque Khan, A. Ramaprakash, Durgesh Tripathi, Avyarthana Ghosh, Natalie Krivova, Subhamoy Chatterjee, Dipankar Banerjee, Pravin Chordia, Achim Gandorfer, Dibyendu Nandy, Chaitanya Rajarshi, Sami Solanki, S. Sriram

Proceedings Volume 9905, 990503 (2016) https://doi.org/10.1117/12.2232266

KEYWORDS: Space operations, Ultraviolet radiation, Space telescopes, Telescopes, Space telescopes, Solar processes, Sensors, X-ray imaging, Plasma, Ions, Magnetosphere

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Proceedings Article | 8 July 2014 Paper

Project status of the Robert Stobie spectrograph near infrared instrument (RSS-NIR) for SALT

Marsha Wolf, Mark Mulligan, Michael Smith, Douglas Adler, Curtis Bartosz, J. Christopher Clemens, Kristine Garot, Briana Indahl, Kurt Jaehnig, Ron Koch, Gregory Mosby, Kenneth Nordsieck, Jeffrey Percival, J. Alan Schier, Andrew Sheinis, Stephen Smee, Donald Thielman, Mark Werner, Matthew Bershady, David Buckley, Mahesh Burse, Pravin Chordia, Harland Epps, William Mason, Theodore Williams, Jeffrey Wong, Sujit Punnadi, Anamparambu Ramaprakash

Proceedings Volume 9147, 91470B (2014) https://doi.org/10.1117/12.2056736

KEYWORDS: Sensors, Cameras, Near infrared, Diffraction gratings, Beam splitters, Optical filters, Collimators, Received signal strength, Spectroscopes, Telescopes

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Proceedings Article | 20 July 2010 Paper

Controller and data acquisition system for SIDECAR ASIC driven HAWAII detectors

Sakya Sinha, Sujit Punnadi, Pravin Chordia, Abhay Kohok, Mahesh Burse, Vilas Mestry, Anamparambu Ramaprakash, Kalpesh Chillal

Proceedings Volume 7742, 77422I (2010) https://doi.org/10.1117/12.858455

KEYWORDS: Sensors, Data acquisition, Human-machine interfaces, Staring arrays, Field programmable gate arrays, Cryogenics, Astronomy, Electrons, Interfaces, Readout integrated circuits

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Showing 5 of 14 publications

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