A5055633262- Adaptive optics and wavefront sensing
- Calibration and Measurement Techniques
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Optical Systems and Laser Technology
- Astro and Planetary Science
- Spectroscopy and Laser Applications
- Gamma-ray bursts and supernovae
- Advanced optical system design
- CCD and CMOS Imaging Sensors
- Atmospheric Ozone and Climate
- Advanced Measurement and Metrology Techniques
- Astronomical Observations and Instrumentation
- Optical Polarization and Ellipsometry
- Photocathodes and Microchannel Plates
- Solar and Space Plasma Dynamics
- Planetary Science and Exploration
- Photonic and Optical Devices
- Spacecraft and Cryogenic Technologies
- Optical measurement and interference techniques
- Optical Coatings and Gratings
- Dyeing and Modifying Textile Fibers
- Congenital Ear and Nasal Anomalies
- Optical and Acousto-Optic Technologies
- Advanced Chemical Sensor Technologies
Royal Victoria Infirmary
2025
Indian Institute of Astrophysics
2015-2024
Christ University
2020-2024
SASTRA University
2020
Abstract The Ultra-Violet Imaging Telescope (UVIT) is one of the payloads in ASTROSAT, first Indian Space Observatory. UVIT instrument has two 375 mm telescopes: for far-ultraviolet (FUV) channel (1300–1800 Å), and other near-ultraviolet (NUV) (2000–3000 Å) visible (VIS) (3200–5500 Å). primarily designed simultaneous imaging ultraviolet channels with spatial resolution better than 1.″8, along provisions slit-less spectroscopy NUV FUV channels. results in-orbit calibrations are presented this paper.
ASTROSAT is India's first astronomy satellite that will carry an array of instruments capable simultaneous observations in a broad range wavelengths: from the visible, near ultraviolet (NUV), far-UV (FUV), soft X-rays to hard X-rays. There be five principal scientific payloads aboard satellite: (i) Soft X-ray Telescope (SXT), (ii) three Large Area Xenon Proportional Counters (LAXPCs), (iii) Cadmium-Zinc-Telluride Imager (CZTI), (iv) two Ultra-Violet Imaging Telescopes (UVITs) one for visible...
Results of the initial calibration Ultra-Violet Imaging Telescope (UVIT) were reported earlier by Tandon et al. (2017). The results based on ground as well first observations in orbit. Some additional data from and more in-orbit have been used to improve results. In particular, extensive new obtain (a) photometric which includes (i) zero-points (ii) flat fields (iii) saturation, (b) sensitivity variations (c) spectral for near Ultra Violet (NUV; 2000 - 3000 Angstroms) far (FUV; 1300 1800...
Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far (FUV; 130 -180 nm), Near (NUV; 200 -300 nm) and Visible band (VIS; 320-550nm) imagers.ASTROSAT the first multi wavelength INDIA.UVIT will image selected regions sky simultaneously in three channels & observe young stars, galaxies, bright UV Sources.FOV each 3 ~ 28 arc-minute.Targeted angular resolution resulting images better than 1.8 arc-second (better 2.0 for visible channel).Two identical co-aligned telescopes...
We present the in-orbit performance and first results from ultra-violet Imaging telescope (UVIT) on ASTROSAT. UVIT consists of two identical 38cm coaligned telescopes, one for FUV channel (130-180nm) other NUV (200-300nm) VIS (320-550nm) channels, with a field view 28 $arcmin$. The detectors are operated in high gain photon counting mode whereas detector is low integration mode. channels have filters gratings, has filters. ASTROSAT was launched 28th September 2015. verification carried out...
The Solar Ultraviolet Imaging Telescope (SUIT) is an instrument onboard the Aditya-L1 spacecraft, first dedicated solar mission of Indian Space Research Organization (ISRO), which will be put in a halo orbit at Sun-Earth Langrage point (L1). SUIT has off-axis Ritchey–Chrétien configuration with combination 11 narrow and broad bandpass filters used for full-disk imaging Ultravoilet (UV) wavelength range 200-400 nm. It provide near simultaneous observations lower middle layers atmosphere,...
Ultra Violet Imaging Telescope on ASTROSAT Satellite mission is a suite of Far (FUV; 130 - 180 nm), Near (NUV; 200 300 nm) and Visible band (VIS; 320-550nm) imagers. first multi wavelength INDIA. UVIT will image the selected regions sky simultaneously in three channels & observe young stars, galaxies, bright UV Sources. FOV each 3 ~ 28 arc-minute. Targeted angular resolution resulting images better than 1.8 arc-second (better 2.0 for visible channel). Two identical co-aligned telescopes (T1,...
The Thirty Meter Telescope (TMT) is a future generation telescope proposed to be located in Mauna Kea, Hawaii or La Palma the Canary Islands. will have segmented primary and an inclined tertiary mirror. segmentation of mirror inclination can introduce significant polarization aberrations. Typically, aberrations, introduced due coating high incident angles cause small modifications Point Spread Function (PSF). Here, we perform ray tracing for TMT using optical design software Zemax different...
Abstract First-time airglow observations of the nighttime thermospheric wind from an in-house developed ground-based Fabry–Perot Interferometer are recorded Kolhapur location India. This was first attempt to build such instrument, and thus quality data in field is satisfactory. The instrument has been thoroughly calibrated laboratory, accuracy important parameter finesse etalon found be ≈94% agreement with value supplied by manufacturer. indicate that vertical observed looking toward Zenith...
The 2.34m Vainu Bappu Telescope (VBT) is a reflecting telescope that operates in two modes, prime focus and cassegrain focus, equipped with instruments. In mode, the has F-number of f/3.25, High-Resolution Echelle Spectrograph (HRES) employed through optical fiber. On other hand, f/13, OMR (OMRS) mounted for low medium-resolution spectroscopy. Currently, VBT faces limitation: either OMRS or HRES can be used due to switch heavy secondary mirror. To overcome this, we present novel method...
In fiber-based spectroscopy within telescopes, a prevailing limitation has been the necessity to align fiber diameter with telescope's seeing conditions, often characterized by Full Width at Half Maximum of point spread function. This alignment constraint captures around 50 \% incoming flux from any source. Furthermore, challenge is compounded when high-resolution in play, as it demands minute slit width, further exacerbating loss. The essence this paper lies comprehensive exploration,...
The upcoming large astronomical telescopes are trending towards the Segmented Primary Mirror due to technological advancements & manufacturing feasibility. We have designed a wide-field optical IR spectroscopic survey telescope that can deliver spectra of several millions sources. baseline design this is 6.2 m segmented primary mirror with hexagonal segments 1.44m size, intersegment Edge sensors, and soft positioning actuators. provide 2.5deg FOV achieved through system wide field corrector...