Biswajit
Jana

Dissertation: Closed-Loop Feedback Control System for the Exoplanet High-Resolution RV Spectrograph (EXOhSPEC) Development

• Star Formation and Evolution; Physics of Astronomical Spectra; High Energy Astrophysics; Galaxy Structure and Evolution
• Foundations of Cosmology; Early Universe and Galaxy Formation; Research Techniques in Astrophysics
• Statistics and Analysis; From Stars to Planets

Dissertation: Dimming Controlled Visible Light Communication System using Raspberry Pi — published in Optical and Quantum Electronics, Springer (2021).

• Developed a closed-loop stabilisation framework for EXOhSPEC, a high-resolution radial-velocity spectrograph testbed for exoplanet instrumentation research.
• Integrated IDS3010 interferometric sensing, Meerstetter TEC control, BME environmental sensors, MaxIm DL centroid tracking, and adaptive-optics correction into Python-based feedback workflows.
• Quantified environmental coupling: 1 hPa pressure → ~0.4 µm OPL; 1°C temperature → ~6 µm OPL variation.
• Achieved ~±0.3°C enclosure stability over multi-week operation, later reaching millikelvin-level TEC control during closed-loop experiments.
• Built diagnostics stack: Grafana + InfluxDB, serial logging, web monitoring, and Python-based OPL and pixel-drift correction models using environmental data and guider centroid errors.
• AO Stage-1 tests validated ~0.15 px/step response; reduced mean post-correction residuals from ~0.44 px to ~0.15 px; hybrid TEC–AO runs reduced dY RMS from ~2.72 px to ~0.69 px.

• Built a live browser-based Gaia DR3 laboratory for exploring stellar populations on the H–R diagram using real catalogue data.
• Implemented 10+ interactive components including H–R diagram view, stellar-region overlays, local 3D Galactic projection, telemetry panels, zoom controls, export tools, and progressive browser-side data loading.
• Solved practical large-CSV handling, browser memory limits, and rendering-performance constraints for client-side science delivery.

• Developed a live exoplanet transit visualisation tool covering transit geometry, normalised light curves, flux dips, limb darkening, and atmospheric transmission.
• Quantitative outputs: transit-depth visualisation, normalised flux curves, ingress/egress interpretation, and planet–star radius-ratio explanation.

• Applied the Binapprox algorithm for efficient median estimation across 9,587 astronomical FITS images.
• Developed image-stacking and median-combination workflows to improve faint-source detectability for pulsar-search style datasets.

• Exoplanets: analysed transit dips and RV variations using DACE, Python, and lightkurve to estimate planetary parameters.
• Brown dwarfs: classified a target as a brown dwarf with estimated T ~1100 K and silicate atmospheric features; proposed further PICASO 3.0 analysis.
• Gaia close encounters: identified GJ710 as a potential close-passage candidate with perihelion-distance and uncertainty analysis.

• CCD calibration, photometry, image acquisition, guiding, and spectroscopic data reduction using Meade telescopes.
• Participated in planetarium demonstrations and public telescope sessions.

• Implemented a Multi-Header Hybrid Pulse Position Modulation VLC system using Raspberry Pi and low-cost hardware.
• Achieved communication distances of ~3 m at dimming 0.25 and ~3.5 m at dimming 0.5/0.75; published in Optical and Quantum Electronics.

• Evaluated microbolometer-camera performance for satellite laser ranging and orbital-debris tracking; constructed link-budget comparisons for microbolometer, CMOS, CCD, and quad-detector systems.
• Modelled detector responsivity, beam divergence, atmospheric transmission, refractive-index effects; proposed improvement routes using high-TCR materials and optical-antenna coupling.

• Analysed VISTA, DES, and WISE survey data for potential halo T dwarf candidates.
• Contributed to candidate assessment, follow-up planning, and a CNTAC telescope-proposal submission for Magellan/FIRE spectroscopic follow-up (2025A).

Hands-on training in exoplanet atmospheric modelling, brown-dwarf atmosphere interpretation, and retrieval tools including PICASO and petitRADTRANS.

Demonstrated a two-element radio interferometer and observed solar transits; practical exposure to radio astronomy instrumentation and interferometry.

Cross-matched optical and radio catalogues and explored machine-learning-based classification using multi-wavelength astronomical data for elliptical-galaxy classification.

Worked on low-cost high-frequency detecting circuits and calibration/synchronisation of multiple drones.