DOI: 10.48322/yggh-9h95
title: Voyager 2 Planetary Radio Astronomy (PRA) Highband Receiver Jupiter encounter, 48 sec resolution

description: 
 Voyager 2 Planetary Radio Astronomy (PRA) Highband receiver daily files
 during Jupiter Encounter (1979-06-01 to 1979-07-30). Associated with these binary data are a series of quick-look GIF spectrogram plots created using the binary data. The plots are available for both polarization channels. These binary data were also converted into IDL save sets.


 The data set provides 48 second resolution highband radio mean power data
 in units of millibels. The high-band receiver consisted of 128 channels of
 200 kHz bandwidth each, with center frequencies spaced at 307.2 kHz
 intervals from 1.2 MHz to 40.4 MHz. The highband receiver was designed
 especially for the observation of Jovian decametric radio emissions. The
 PRA radiometer was usually operated routinely in the so-called POLLO sweeping
 mode, in which all 198 frequency channels of the high- and low-band receivers
 together were swept in 6 sec, dwelling at each channel for 25 msec. From one
 step to the next in the channel switching sequence, the antenna polarization
 sense was reversed, i.e., was changed from RH to LH or vice versa. Thus the
 time required for making a measurement of both the RH and LH intensity
 components at both senses of elliptical polarization at a given frequency was
 12 sec. The data consists of successive averages of 4 pairs of RH and LH
 intensity measurements, each average spanning an interval of 48 sec.

 The format of these binary data files is as follows:

 file separation variable

 year, month, day information

 millisecond decimal value of the day

 Integer array (128,2) for 128 left and right channels (NOTE 128 channels for Hi-band; 70 channels for Lo-band)

 file separation variable

 There is an IDL program that reads these files into an IDL-format save set. See Information URL for a link to this file.

                                                         
      The data are calibrated and are given in units of            
      'millibels' which is 1000 times the log of the received power.         
      Zero millbels corresponds to approximately 1.4 x 10^-21 W m^-2         
      Hz^-1, however, this value is never seen in practice. The              
      minimum values detected, which includes receiver internal and          
      spacecraft generated noise, are about 2300 to 2400 millibels,          
      or about 3.5 x 10^-19 W m^-2 Hz^-1; even higher values are seen        
      at the very lowest frequencies.                                        
                                                                             
   Note:    
      The polarization indicated is the received polarization, not               
      necessarily the emitted polarization. Correct interpretation of        
      the received polarization depends on the antenna plane                 
      orientation relative to the radio source. A good description of        
      this concept can be found in
     
      Leblanc Y., Aubier M. G., Ortega-Molina A.,
      Lecacheux A., 1987, J.Geophys. Res. 92, 15125 and in
     
      Wang, L. and Carr, T.D.,
      Recalibration of the Voyager PRA antenna for polarization sense
      measurement, Astron. Astrophys., 281, 945-954, 1994. and references therein.