Trigger A8 Description

Sequence: S05,...
Trigger A8 ( RNGSAT, Rings & Satellite Regions )
This mode assumes a background survey mode, such as 8A or A0, is running, and on top of that overlays fast WFR data acquisition. In order to do this, the LFDR data acquisition is stopped (it can be synthesized on the ground, using the fast WFR data.) A WFR snapshot, in its nominal 5-channel and 2048-sample mode, is acquired every 24 seconds. The WFR is run in toggle mode, so these snapshots alternate between 25 Hz mode and 2.5 KHz mode. In addition to stopping the LFDR data acquisition, the data compression algorithm for the WFR is changed to "packed" mode, so that this faster data rate can be accomplished. The target bit rate is 5800 bps. During C35, in a short test, the measured bit rate was 5700 bps; this was using trigger 8A as the background trigger.

Receiver	Frequency Range	Sensors	Time between Snapshots
MFR	25 - 12 KHz	EX, BZ	32 seconds
WFR	1 - 25 Hz	EX,EW,BX,BY,BZ	48 seconds
WFR	.1 - 2.5 KHz	EX,EW,BX,BY,BZ	48 seconds
HFR	3.6 KHz - 16 MHz	EX, EW	8 seconds
LP	N/A	Langmuir Probe	640 seconds
Sounder	3.6 - 115 KHz	EX, EW	600 seconds

The HFR is in a modified "Composite Survey" mode, which now includes both auto- and cross-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    500  1              3.6-319KHz
HF1   2E    y     y        2    n     40  1     60    25 0.325-1.825MHz
HF2   1E    n     n        1    n     40  1     72   200 1.825-16.225MHz

Bands ABC require 1.580 sec to complete, H1 requires 2.852 sec, and
H2 requires 2.534 sec for a total of 6.966 sec per sweep.  The hfr
cycle time is 8.000 seconds.

Every 600 seconds the HFR normal analyses are interrupted by a Sounder analysis. The Sounder operation has a duration of approximately 40 seconds. This Sounder analysis is defined by:

Sounder Mode: Ex AAA
1st  Sounder Frequency:   0
last Sounder Frequency:  89
T1 delay:   5 milliseconds
T2 delay:   5 milliseconds
T3 delay:  15 milliseconds
Passive Spectra:   2
Active  Spectra:   2
No. of Cycles:     1
Sounder Output A:   3 Autos
Sounder Output B:   3 AGCs