| Author(s) and Co-Author(s) with Affiliation: Prasanna Deshmukh(Indian Institute of Astrophysics, Bangalore - 560034, India), D. V. S. Phanindra(Indian Institute of Astrophysics, Bangalore - 560034, India), Tsewang Stanzin(Indian Astronomical Observatory (IAO), IIA, Hanle, Ladakh - 194101, India), Sonam Jorphail(Indian Astronomical Observatory (IAO), IIA, Hanle, Ladakh - 194101, India), Tashi Tsering Mahay(Indian Astronomical Observatory (IAO), IIA, Hanle, Ladakh - 194101, India), Tsewang Gyalson(Indian Astronomical Observatory (IAO), IIA, Hanle, Ladakh - 194101, India), Tsewang Dorjai(Indian Astronomical Observatory (IAO), IIA, Hanle, Ladakh - 194101, India), Amit Kumar(Indian Institute of Astrophysics, Bangalore - 560034, India), Dorje Angchuk(Indian Astronomical Observatory (IAO), IIA, Hanle, Ladakh - 194101, India) |
| Abstract: The HCT control system upgrade activity is currently underway at the Indian Institute of Astrophysics. As a part of this, a dedicated vibration measurement campaign was conducted on the 2-m Himalayan Chandra Telescope (HCT) in August 2025 using high-sensitivity accelerometers (ADXL355) and a custom-built, high-speed data logger. The accelerometer sensors were installed at structurally significant places on the telescope to capture broadband and transient disturbances caused by the structure, axis motion, wind loading, and other subsystems. By high-rate measurements, we were able to extract the vibration spectra, modal characteristics, coherence between structural components, and temporal evolution under tracking and slewing, which directly impact pointing stability and wave-front quality. The findings provide essential input for optimizing the HCT control system architecture and improving vibration rejection performance. The experiment has also validated the importance of incorporating these vibration sensors as a monitoring and diagnostics system with the HCT control system upgrade. |
