Phase III of USO Solar Vector Magnetograph

TL;DR

This paper describes the third development phase of the USO Solar Vector Magnetograph, highlighting key upgrades like a new guiding system, high-cadence spectropolarimetry, and expanded spectral line observations for improved solar magnetic field measurements.

Contribution

It introduces three major improvements in the instrument's design and capabilities, enhancing solar magnetic field observations and chromospheric studies.

Findings

Successful implementation of a web-camera based guiding system

High-cadence spectropolarimetry achieved with Liquid Crystal Variable Retarders

Inclusion of Na D1 line for chromospheric observations

Abstract

The Solar Vector Magnetograph (SVM) is a modern imaging spectropolarimeter installed at Udaipur Solar Observatory (USO). Earlier phases saw the development of the instrument using off-the-shelf components with in-house software development. Subsequently, improvements were done in the opto-mechanical design of the sub-systems and the telescope tracking system. The third phase of the instrument development saw three major improvements, these include: (i) installation of a web-camera based telescope guiding system, developed in-house, (ii) high-cadence spectropolarimetry using Liquid Crystal Variable Retarders and a fast CCD camera and (iii)inclusion of Na D1 line with regular photospheric Fe 630.2 nm line for chromospheric observations.