PDS_VERSION_ID         = PDS3                                                 
RECORD_TYPE            = STREAM                                               
OBJECT                 = TEXT                                                 
  PUBLICATION_DATE     = 2006-12-20                                           
  NOTE                 = "                                                    
      TRIG_94.TXT describes the RPWS instrument configuration for the         
      High Frequency Receiver (HFR), the Medium Frequency Receiver            
      (MFR), the Low Frequency Receiver (LFR), the Waveform Receiver          
      (WFR), the Langmiur Probe (LP), and the Sounder when using Trigger      
      94."                                                                    
END_OBJECT           = TEXT                                                   
END                                                                           

Trigger 94 Description                                                        
                                                                              
Sequence:  C27                                                                
Trigger 94 ( Aurora/SKR Mode, outside source crossing & low latitudes )       
                                                                              
This mode is designed to provide a survey mode with full direction-finding    
(DF-3) up to 1.8 MHz.                                                         
                                                                              
Both low and high frequency WFR measurements are made.  In high-frequency     
mode, there are 512 samples taken for the EX, EW, and BX antennas.  These     
channels are also analyzed onboard using the LFDR FFT software, and the LFDR  
data is provided in addition to the waveform data.  In low-frequency mode,    
5-channel 1024-sample WFR measurements are made every 64 seconds.             
                                                                              
Langmuir Probe sweeps are performed every 32 seconds; density measurements    
are made at a 100-Hz sampling rate to match the Low-Frequency WFR             
measurements.  A simple up-going ramp sweep is performed; with a future       
software update, this will become a down-going voltage ramp.                  
                                                                              
A Sounder measurement replaces the HFR data every 320 seconds.                
                                                                              
Receiver  Frequency Range   Sensors         Snapshot Spacing                  
--------  ----------------  --------------  ----------------                  
LFR       0.1 - 2.5 KHz     EX, EW, BX      32 seconds                        
MFR       25 - 12 KHz       EZ, BZ          32 seconds                        
WFR(LF)   1 - 25 Hz         EX,EW,BX,BY,BZ  64 seconds                        
WFR(HF)   0.1 - 2.5 KHz     EX,EW,BX        32 seconds                        
HFR       3.6 KHz - 16 MHz  EU, EV, EW, EX  32 seconds                        
LP        N/A               Langmuir Probe  32 seconds                        
Sounder   3.6 - 115 KHz     EX, EW          320 seconds                       
                                                                              
                                                                              
                                                                              
                                                                              
The HFR is in direction-finding mode for bands A, B, C, and H1.  This mode    
is defined by:                                                                
                                                                              
                                                                              
          Correlations Channels    Integ.           Size Frequency            
Band Ant. Auto- Cross- per Band df Period Rep Steps kHz  Start - Stop         
---- ---- ----- ------ -------- -- ------ --- ----- ---- ------------         
ABC  2E   y        y      8     y  1000   1              3.6-319 kHz          
H1   2E   y        y      1     y  80     1   60    25   325kHz-1.8MHz        
H2   1E   n        n      1     n  20     1   72    50   1.8kHz-16MHz         
                                                                              
Bands ABC require 6.42 sec to complete, H1 requires 10.31 sec, and H2         
requires 1.46 sec for a total of 18.19 sec per sweep.  However, the time      
between analyses is set to 32 seconds, in order to reduce interference due    
to antenna-switching done during the direction-finding measurements.  Every   
320 seconds the HFR normal analyses are replaced by a Sounder analysis.  The  
Sounder operation has a duration of approximately 40 seconds.  This Sounder   
analysis is defined by:                                                       
                                                                              
                                                                              
  sounder mode:   EZ AAA                                                      
  1st  sounder freq:      0                                                   
  last sounder freq:     89                                                   
  T1 delay:        10 msec                                                    
  T2 delay:        25 msec                                                    
  T3 delay:        25 msec                                                    
  passive spectra:      2                                                     
  active  spectra:      2                                                     
  # of cycles:       1                                                        
  sounder output A:      3 autos                                              
  sounder output B:      3  AGCs