HIAC
CSAC Spectro-Polarimetric Data Visualization Tools
AZAM | CAZAMAZAM
The AZAM utility was developed at HAO in the 1990s as an interactive, multi-purpose tool for analysis and display of data from the Advanced Stokes Polarimeter. Largely the work of Paul Seagraves, AZAM is written in IDL. Among its many features, with AZAM, one may:
- Interactively resolve the inherent 180° ambiguity of the magnetic field azimuth that is present in any measurement that uses polarization.
- Display the vector magnetic field in a number of ways: color images, arrows, contours.
- Interactively display the observed Stokes polarization spectral images along side of the individual Stokes polarization profiles of selected spatial locations.
- Interactively display the values of individual instances of the extracted magnetic and atmospheric parameters.
- Display the 2-dimensional images of the fitted quantities (i.e., Doppler shifts, line strength, fill fractions, field inclination).
- Display vector field properties in either the observer's frame or the "zenith frame" (as if the observer were looking directly down on the observed portion of the solar disk).
- Display images in solar coordinates (longitude, latitude), appropriately mapped to the grid on a spherical surface.
- Output images to PostScript for printing or other applications Blink images of different parameters against each other.
As part of the Ambiguity Resolution Workshop, a head-to-head test of many methods for resolution of the ambiguity was carried out. In all test cases, AZAM exceeded the performance of any other method. However, AZAM is a manual method for resolving the ambiguity, so the success of its use depends heavily on the experience and knowledge of the user. Nonetheless, it remains a very useful tool for this important piece of the task of measurement of solar vector magnetic fields.
AZAM is slated to be adapted to the output of the MERLIN inversion in mid-2008 and will become CAZAM (see below). A screenshot of an AZAM session operating on data from the Advanced Stokes Polarimeter is shown below.
CAZAM
We have not yet begun work on translating AZAM to work with MERLIN or LILIA output. However, we plan to exploit the features of IDLs Object Graphics capabilities in developing the code for CAZAM. Watch this space.