Kuhn et al. (1994) obtained IR spectra during the 1994 eclipse. They detected a line of S IX at 1.252 microns for the first time, the strong lines of Fe XIII, and, building on an earlier aircraft-based detection during the 1966 eclipse by Munch et al. (1967), an important line of Si X at 1.43 microns.

Using the 40 cm Evans coronagraph, Penn & Kuhn (1994) measured the important 1.43 micron line of Si X, deriving an accurate rest wavelength and intensity. Penn & Kuhn also secured accurate new wavelengths for the Fe XIII infrared lines.

Kuhn et al. (1999) obtained data in a filter near 3.93 microns from an aircraft platform during the eclipse of 28 February 1998, aiming to detect the line of Si IX predicted to be strong by Judge in 1998. With EUV data of lines of Si IX, Kuhn et al. tentatively claimed a detection of the 3.93 micron line of Si IX. Judge et al. (2002) followed up with spectroscopic measurements of the same line using the McMath-Pierce telescope on Kitt Peak, and were able not only to provide a definitive detection, but also to measure a new rest wavelength which places the blue wing of the line under a strong telluric N2O line. In the active regions observed, the line's intensity is comparable to or larger than predicted in earlier work for the quiet Sun.

Unpublished work by Elmore and Judge on data sampled near kHz frequencies at the Mk IV coronagraph on Mauna Loa shows that the passage of dust and/or bugs between the telescope and sun can be expected to dominate spurious signals which can, for poor sites, dominate the noise expected in coronagraph measurements of the corona.

Kuhn et al. (2003) designed and constructed the prototye SOLARC off-axis reflecting coronagraph. Important science results were reported by Lin et al. (2004), who also reportred the first results with a new fiber-fed IR spectrograph.

Tomczyk and colleagues ( Darnell et al. 2003, Tomczyk 2003) have developed a new multi-channel polarimeter for coronal magnetic field measurements (COMP). The instrument uses tunable Lyot filters with widths of roughly 0.1 nm, and observes lines of He I and Fe XIII between 1.075 and 1.083 nm. The instrument has been operated since then at the 20cm ``One-Shot'' corongraph on Sacramento Peak developed by Smartt. First results have been presented by Tomczyk et al. (2004).

As already noted, full statistical equilibrium calculations including collisional depolarization have been made for both Fe XIV and Fe XIII were made by Sahal-Brechot (1974a), Sahal-Brechot (1974b), ( House 1977, Sahal-Brechot 1977, and House et al. 1982). Querfeld (1982) derived a method to "invert" the magnetic dipole data for Fe XIII lines. These methods are put in context by paper V in a series by Judge and colleagues (see below).

Penn et al. (2004) studied the influence of background noise-induced statistical errors in the determination of thermal and magnetic parameters, in particular from the Fe XIII magnetic dipole lines.

The article by Judge (1998) is the first in a series of, so far, five articles in the series "Spectral Lines for Polarization Measurements of the Coronal Magnetic Field". The second article provides a consistent theoretical treatment of the formation of the magnetic dipole lines ( Casini & Judge 1999, see erratum). The third ( Brage et al. 2000) computed atomic data for Si IX. The fourth, "Stokes Signals in Current-carrying Fields" ( Judge et al 2006), presents the first simulations of the magnetic dipole signals in current carrying (i.e. non-potential) fields. The morphology of maps of linear polarization is found to be particularly sensitive to the existence and strength of the current sheets, as field lines wrap around them according to the Biot-Savart law. Measurements of magnetic dipole lines can in principal reveal the presence and nature of current systems in the corona, potentially a major step in coronal physics. The fifth paper (Judge 2006, in draft form) studies the information content of magnetic dipole lines, starting with inverse methodology but examining other methods (forward modeling, tomography, simple "one-point" diagnostic methods), and develops a method by which the well known Van Vleck ambiguity might be resolved.

In parallel, Lin & Casini (2002) developed the classical theory for the formation of the "normal" J=1 to J=0 transitions.

Judge & Casini (2001) have written a computer program for the general calculation of magnetic dipole coronal lines based upon the formalism of ( Casini & Judge 1999). Results are presented there and in ( Judge et al 2006), where the formalism for particle collisions is discussed in an appendix.

Kramar & Inhester have studied how tomography might be used to determine magnetic fields, together with constraints from photospheric magnetic field measurements and the divergence-free condition (see their articles from 2004, 2005 and 2006. The technique appears promising, Stokes I,V data recovering many aspects of models with both potential and current-carrying fields using 1 observation per day for 14 days or so (half a solar rotation). However, data obtained from vantage points in the ecliptic plane alone is sensitive only to certain magnetic field structures. Full vector field reconstructions require either observations from higher heliographic latitudes, or observations including the linear polarization components. (To avoid potential confusion, note that Kramar & Inhester call the linear polarization induced by resonance scattering in magnetic dipole lines the "Hanle effect". This is not quite correct- the lines are formed in the very strong field limit of the Hanle effect in which the sub-levels therefore evolve incoherently).