Together with Peter Wilson of the University of Sydney, I am obtaining high-resolution magnetograms here at BBSO in order to observe the reversal of the solar polar magnetic fields in the current solar cycle.
Results from earlier work in this project can be found here Right now are are continuing to use the BBSO Video Magnetograph to obtain our images. We expect later this year to be using the new all-digital magnetograph currently under development at the Center for Solar Research at NJIT. This instrument should give greater sensitivity and allow us to use shorter exposure times than we are currently.
We have recently adopted the flat-fielding technique developed by Jongchul Chae here at BBSO. It gives much better results than our previous method.
Each mosaic is made up of five individual magnetograms. Each mosaic is rotated so that the heliographic poles are at the top and bottom of the page, with north at the top and east on the left. The images are scaled so that +/- 30 gauss is either full white or full black. These images do not include a correction for the projection angle of the magnetic field.
Here is a movie of our 1999 February 23 south pole data remapped to Cartesian coordinates. You can see the solar rotation.