Zeemanfit: Use and Development of the solis_vms_zeemanfit code

The purpose of the SOLIS Zeemanfit Code is to provide a straight-forward, easily checked measure of the total magnetic-field strength in the high-strength umbral regions of the solar disk. In the highest-strength regions, the Zeeman splitting of the 6302-angstrom Fe line becomes wide enough for the triplet nature of the line to be visible by eye in non-polarized light. Therefore, a three-line fit to the spectra should, in principle, provide a fairly robust measure of the total magnetic-field strength. The code uses the Level-1.5 spec-cube data of the SOLIS VSM 6302-vector observations (specifically the Stokes-I and Stokes-V components) to fit the line profiles at each appropriate pixel and calculate the magnetic-field-strength from the line-center separation of the two fit 6302.5 sigma-components. The 6301.5-angstrom Fe line is also present and fit in the VSM 6302-vector data, but it is an anomalous-Zeeman line with a weaker response to magnetic fields. Therefore, no magnetic- field measure is derived from this portion of the spectral fit.