| Name: | Prasanna Deshmukh |
| Affiliation: | Indian Institute of Astrophysics |
| Conference ID: | ASI2025_341 |
| Title: | Integrated Modelling of 6.2m Wide-Field Telescope for Spectroscopic Survey. |
| Authors: | Prasanna Deshmukh 1, Sriram S 2,1, Totan Chand 1, Sudharsan Kambhala 1, Ramya S 1, Ravi Joshi 1, Yerra Bharat Kumar 1 |
| Authors Affiliation: | 1 Indian Institute of Astrophysics, Bengaluru, 560034, India
2 CHRIST Deemed to be University, Bengaluru, 560029, India |
| Mode of Presentation: | Poster |
| Abstract Category: | Facilities, Technologies and Data science |
| Abstract: | 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 of astronomical sources. The baseline design of this telescope is a 6.2 m segmented primary mirror with 19 hexagonal segments of 1.44m size, 84 edge sensors, and 57 soft actuators. The telescope is designed to provide a 2.5deg FOV achieved through a system of wide field corrector lenses with a design residual <0.2". Also, it delivers an f/3.6 beam suitable for directly feeding optical fibres. A mechanical concept of the telescope is designed with a truss-based mirror cell to support the segmented primary mirror and keep the deformation to a minimum. As the primary mirror is segmented, the deformation due to different disturbances like wind, vibration, thermal effects must be corrected to a nanometer accuracy to make it act like a monolithic primary mirror. This is achieved through an active control system using three actuators and six intersegment edge sensors. In addition to these disturbances atmospheric seeing also degrades the image quality which can be corrected by using Adaptive Optics. An integrated model using codeSMT telescope simulation tool, is built. It is based on the state-space model of a soft actuator with Multiple-Input Multiple-Output (MIMO) capability to incorporate dynamic wind disturbance from the IAO Hanle site, thermal and vibration effects. A detailed error multiplier analysis is performed numerically using this tool and is in good agreement with analytical calculations. A parameter sensitivity analysis is performed to fine-tune the primary mirror control system variables. This paper presents the integrated modeling based performance analysis of a 6.2m wide-field telescope currently under conceptual design. |
