Trigger BE Description

Sequence: C40, ...
Trigger BE ( Titan millisecond mode)
This mode assumes a that either Nighttime survey 8E or SEDDF mode A0, is running. The HFR runs in millisecond mode for approximately 56 seconds of every 64-second interval, and then performs one normal analysis using fast time constants. The millisecond mode frequency is changed every 64 seconds, stepping from 775 KHz to 1525 KHz, and finally to 3025 KHz. The WFR is run in the usual 5-channel mode, except that its 3rd channel, normally connected to BX, is now connected to the Langmuir Probe sphere, which is set to a fixed bias of +4V. The LP performs a sweep every 640 seconds, and between sweeps does a fixed bias (+4V) density mode measurement every 16 seconds.
The WBR acquires data in 80-KHz mode. Sounder is disabled, and dust detection is disabled in this mode. The target bit rate is 100 kbps. In C40 the measured bitrate was 99 kbps. There was an error in the C40 test --- because the preceding mode was normal survey (8A) instead of the recommended 8E or A0, the HFR performed its normal analysis every 72 seconds instead of the planned 64 seconds.

Receiver Frequency Range Sensors Time between Snapshots
MFR 25 - 12 KHz EX, BZ 32 seconds
WFR 1 - 25 Hz EX,EW,LP(+4V),BY,BZ 320 seconds
WFR .1 - 2.5 KHz EX,EW,LP(+4V),BY,BZ 320 seconds
HFR 3.6 KHz - 16 MHz EX, EW 64 seconds
HFR millisecond mode at 775, 1525, 3025 KHz EX 2.5 seconds
LP N/A Langmuir Probe 640 seconds
WBR 0 - 80 KHz EX 0.125 second


The HFR is in a modified "Composite Survey" mode, which includes both auto- and cross-correlations for H1, and should be set up to use the faster integration constants of the "Night-time" survey mode, running either trigger 8E or A0 or A8 prior to this trigger. 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    20        1     60    25   325k-1.8MHz
H2   1E   n         n         1       n    10        1     72    200  1.8M-16MHz
Bands ABC require 3.16 sec to complete, H1 requires 1.57 sec, and H2 requires 0.65 sec for a total of 5.62 sec per sweep. However, the time between analyses is set to 10 seconds to avoid interference from the LP sweep.

No Sounder measurements are made in this mode. No onboard dust detection is done either.