Trigger 76 Description

Sequence: C21, etc.
Trigger 76 ( Titan low-rate Langmuir Probe Mode )
This mode is designed to provide a survey mode, with standard temporal resolution and spectral resolution, and with increased Langmuir Probe measurements designed for Titan flybys. High-frequency WFR measurements are made. Langmuir Probe sweeps are performed every 16 seconds using the down-up ramp bias function. Between the 1-second sweeps, 20-Hz LP density measurements are done. No Sounder or Dust measurements are made. The HFR is in Composite Mode Survey. During Cruise, this mode has been used periodically to monitor Spacecraft potential and photoelectrons.

Receiver Frequency Range Sensors Time between Snapshots
LFR 1 - 25 Hz EX, BX 32 seconds
MFR 25 - 12 KHz EX, BZ 32 seconds
WFR 0.1 - 2.5 KHz EX,EW,BX,BY,BZ 320 seconds
HFR 3.6 KHz - 16 MHz EX, EW 10.375 seconds
LP N/A Langmuir Probe 16 seconds

The HFR is in a modified "Composite Survey" mode, which now includes both auto- and cross-correlations for H1. Prior to C28, this mode did not include auto-correlations for 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        16       n    1000      1                3.6-319 kHz
H1   2E   y         y         2       n    80        1     60    25   325k-1.8MHz
H2   1E   n         n         1       n    20        1     72    200  1.8M-16MHz
Bands ABC require 3.16 sec to complete, H1 requires 5.47 sec, and H2 requires 1.46 sec for a total of 10.09 sec per sweep. However, a small amount of additional time is required for commanding and data formatting, resulting in a 10.375 cycle time.