> Good day- > I'd like to overlay range rings on a NLDN lightning map that I am creating. I > am unsure of where to start with this process. Is there a program that I can > use to complete such a task? Hi Darren, Lightning are point data in GEMPAK and can be plotted with programs like sfmap and gpmap. With the way gempak program use the X windows graphics device, you can call multiple gempak programs in a script to overlay images, text and other graphics. There is a program called gpanot ( http://www.unidata.ucar.edu/software/gempak/man/prog/gpanot.html ) that can overlay range rings in the form of SHAPE = regpoly INFO = 1/1.0/360/360 along with other parameters such as LOCI for where to place. There's an old thread archived about this here: http://mailman.unidata.ucar.edu/support/help/MailArchives/gempak/msg03234.html Hope this help. -Michael Ticket Details =================== Ticket ID: WJJ-693443 Department: Support GEMPAK Priority: Critical Status: Open