NAME: iug_plot2d_ionogram PURPOSE: Generate several ionogram plots from the ionogram data taken by the ionosonde. SYNTAX: iug_plot2d_ionogram, valuename=valuename KEYWOARDS: VALUENAME = tplot variable names of ionosonde observation data. For example, iug_plot2d_ionogram,valuename = 'iug_ionosonde_sgk_ionogram'. The default is 'iug_ionosonde_sgk_ionogram'. CODE: A. Shinbori, 11/01/2013. MODIFICATIONS: A. Shinbori, 09/01/2014. ACKNOWLEDGEMENT: $LastChangedBy: jimm $ $LastChangedDate: 2014-02-11 10:52:58 -0800 (Tue, 11 Feb 2014) $ $LastChangedRevision: 14325 $ $URL $