To create and IDL SAV file from a RIQ file
IDL> riq_idl,'WI937_2011191140105.RIQ'

This take about a minute to run

Now we can run the plotting code:
IDL>pulse,'WI937_2011191140105.sav'

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

To open and play with the SAV file
IDL>restore,'WI937_2011191140105.sav'

To see what is in the file
IDL>help

This prints:
% At $MAIN$          
MONITOR         UNDEFINED = <Undefined>
PCT             STRUCT    = -> <Anonymous> Array[1]
PULSE_I         INT       = Array[9952, 448, 8]
PULSE_Q         INT       = Array[9952, 448, 8]
SCT             STRUCT    = -> <Anonymous> Array[1]

You can print out ten consecutive array values
IDL>print,PULSE_I[0,50:60,3]
This prints rangegates 51 through 61 for the first pulse for rx 4

Or you can see what is in PCT
IDL>help,pct
Part of what this prints is:
** Structure <755f58>, 19 tags, length=955392, data length=955392, refs=1:
   RECORD_ID       LONG      Array[9952]
   PRI_UT          DOUBLE    Array[9952]
   PRI_TIME_OFFSET DOUBLE    Array[9952]
   BASE_ID         LONG      Array[9952]
   PULSE_ID        LONG      Array[9952]
   RAMP_ID         LONG      Array[9952]
   REPEAT_ID       LONG      Array[9952]
   LOOP_ID         LONG      Array[9952]
   FREQUENCY       LONG      Array[9952]


So you can see the frequency for a given pulse... lets do pulse 100
IDL> print,pct.frequency[99]
          4108