Trigger B4 Description

Sequence: S05, ...
Trigger B4 ( Titan deltaN/N mode)

This mode assumes a background survey mode, such as 8A or A0, is running. The duty cycle of the Langmuir Probe and the WFR are increased. The WFR is connected in 3-channel mode to the two voltage-biased cycliners, EU and EV, and their voltage is set to +5V. The third WFR channel is connected to the LP sphere, which is biased at +4V. Every 24 seconds a 2048-sample (per channel) data set is acquired by the WFR in 2.5KHz mode. The Langmuir Probe performs a sweep every 20 seconds and between sweeps, does a 356-sample density mode measurement at 20 Hz. The MFR is connected to the EW antenna, since the EX antenna is being used in deltaN/N mode.

Also the LFDR and MFDR use the EW antenna for their electric field measurements (in addition to the BX antenna). They each acquire data once a minute. 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. Measured bitrate was about 55 kbps when in S&ER-3 mode, measured during C39. In C40, at a higher rate telemetry mode, the measured bitrate was 99 kbps.

Receiver	Frequency Range	Sensors	Time between Snapshots
LFR	1 - 25Hz	EW, BX	64 seconds
MFDR	70Hz - 1.7KHz	EW, BX	64 seconds
MFR	25 - 12 KHz	EW, BZ	32 seconds
WFR	.1 - 2.5 KHz	EU(+5V),EV(+5V),LP(+4V)	24 seconds
HFR	3.6 KHz - 16 MHz	EX, EW	10 seconds
LP	N/A	Langmuir Probe	20 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    500  1              3.6-319KHz
HF1   2E    y     y        2    n     20  1     60    25 0.325-1.825MHz
HF2   1E    n     n        1    n     10  1     72   200 1.825-16.225MHz

Bands ABC require 1.580 sec to complete, H1 requires 1.573 sec, and
H2 requires 0.886 sec for a total of 4.039 sec per sweep.  The hfr
cycle time is 10.000 seconds.

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.