After choosing an event for analysis, see the light curves.
Calibrated data is already prepared in XDR (IDL save) format
for important events. So restore it first,
IDL> file=getenv('NORP_XDR')+'/1999/08/norp19990828_0056.xdr' 
CR
IDL> restore,file CR
For plots,
IDL> mfreq=0 CR
IDL> norp_plot,mfreq,mvd,tim,fi CR
Here mfreq is the number of the data identifying the frequency.
For overplotting another frequency data,
IDL> mfreq1=1 CR
IDL> norp_plot,mfreq1,mvd,tim,fi,/over CR