High Resolution Observations using Adaptive Optics: Achievements and Future Needs (2008)
Sankarasubramanian, K., Rimmele, T.
Over the last few years, several interesting observations were obtained with the help of solar Adaptive Optics (AO). In this paper, few observations made using the solar AO are enlightened and...
On the Weakening of Chromospheric Magnetic Field in Active Regions (2008)
Nagaraju, K., Sankarasubramanian, K., Rangarajan, K. E.
Simultaneous measurement of line-of-sight (LOS) magnetic and velocity fields at the photosphere and chromosphere are presented. Fe I line at $\lambda6569$ and $H_{\alpha}$ at $\lambda6563$ are used...
Fine Scale Magnetic Fields in and around a Decaying Active Region (2008)
Sankarasubramanian, K., Hagenaar, H.
High spatial resolution spectro-polarimetric observation of a decaying spot was observed with the Diffraction Limited Spectro-Polarimeter. The spatial resolution achieved was close to the diffraction...
An efficient modulation scheme for dual beam polarimetry (2007)
Nagaraju, K., Ramesh, K. B., Sankarasubramanian, K., Rangarajan, K. E.
An eight stage balanced modulation scheme for dual beam polarimetry is presented in this paper. The four Stokes parameters are weighted equally in all the eight stages of modulation resulting in...
Rajaguru, S. P., Sankarasubramanian, K., Wachter, R., Scherrer, P. H.
We show that the use of Doppler shifts of Zeeman sensitive spectral lines to observe wavesn in sunspots is subject to measurement specific phase shifts arising from, (i) altered height range of...