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 |
Cycle Time |
| MFR |
25 - 12 KHz |
EW, BZ |
32 seconds |
| WFR |
1 - 25 Hz |
EX,EW,LP(+4V),BY,BZ |
48 seconds |
| WFR |
.1 - 2.5 KHz |
EX,EW,LP(+4V),BY,BZ |
48 seconds |
| HFR |
3.6 KHz - 16 MHz |
EX, EW |
64 seconds |
| HFR |
msec mode at 775, 1525, 3025 KHz |
EX |
2.5 seconds |
| LP |
N/A |
Probe |
48 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 32 n 500 1 3.6-319kHz
H1 2E y y 2 n 40 1 60 25 0.325k-1.825MHz
H2 1E n n 1 n 40 1 72 200 1.825M-16.225MHz
Bands ABC require 1.560 sec to complete, H1 requires 2.852 sec, and
H2 requires 2.534 sec for a total of 6.946 sec per sweep. The hfr
cycle time is 64.000 seconds.
No Sounder measurements are made in this mode. No onboard dust detection is done either.