Southwest Research Institute, Department of Space Studies 1050 Walnut St, Suite 300, Boulder, CO 80302, USA; High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, USA
Lockheed Martin Solar & Astrophysics Laboratory, 3251 Hanover St., Org. ADBS, Bldg. 252, Palo Alto, CA 94304, USA
High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307, USA