Souvik Bose worked at the Kiepenheuer-Institut für Sonnenphysik in Freiburg, Germany from August to November 2017 through an EU grant. His tasks involved developing data reduction pipelines for the SPRING feasibility study, which aims to design a new solar network. Specifically, he reduced data from the HELLRIDE instrument on Tenerife and adapted IDL pipelines. He also applied Stokes inversion to HELLRIDE data to determine velocity, temperature and magnetic field maps. From this work he estimated computing needs for intensity, velocity and magnetic field maps from future SPRING observations.

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Certificate of Work for Souvik Bose
This is to certify that Mr. Souvik Bose worked from August 15 – November 15, 2017 at the
Kiepenheuer-Institut für Sonnenphysik in Freiburg, Germany. Souvik Bose received a stipend
through the EU FP7 project Solarnet (High-resolution Solar Physics Network) to cover the costs for
his stay at our institute.
Souvik Bose’s tasks were to work on the development of the data reduction and pipelines in the
framework of the SPRING (Solar Physics Research Integrated Network Group) feasibility study.
SPRING is a work package under Solarnet for designing a new ground-based network of synoptic
observatories of the Sun.
In particular, Mr. Bose was engaged in reducing data from the HELLRIDE (Helioseismic Large
Region Interferometric Device) instrument operated at the Vacuum Tower Telescope on Tenerife.
HELLRIDE is a 2D spectrograph consisting of a dual etalon system with a matrix unit that can hold
a variety of narrowband pre-filters. With its current capabilities HELLRIDE is used as
demonstration instrument for the SPRING post-focus instrumentation.
At the beginning of the internship, Souvik Bose was working on the flatfielding and initial reduction
of the raw data. He adapted and developed data reduction pipelines in IDL (Interactive Data
Language).
Furthermore, he easily applied the Stokes inversion code SIR to determine velocity and
temperature maps for the 2D spectroscopy data in multiple lines that were recorded with
HELLRIDE.
From these studies, he was able to estimate the required computing and processing power for
providing, intensity, velocity, and magnetic field vector maps from the future spectro-polarimetric
observations of SPRING. This is a crucial input for the currently ongoing feasibility study on
SPRING.
PD Dr. Markus Roth
Research Group Leader
Solarent Technical Manager
Kiepenheuer-Institut für Sonnenphysik | Schöneckstrasse 6 | 79104 Freiburg | Deutschland
PD Dr. Markus Roth
Schöneckstraße 6
79104 Freiburg im Breisgau
Germany
Telephone: +49 761 3198-228
Fax: +49 761 3198-111
E-Mail: mroth@kis.uni-freiburg.de
Internet: www.kis.uni-freiburg.de
Freiburg, January 28, 2017