Trigger A4 Description

Sequence: S05,...
Trigger A4 ( HRSED 182 kbps Hirate Mode )

This mode is designed to provide a hirate mode for analyzing fine structure of SED's, while also providing a low temporal resolution spectrum at the spectral resolution. This is accomplished by running the WBR in the "down-convert" mode, using the 25-KHz wide signal provided by the HFR, which is simultaneously running in millisecond at the frequency provided to the WBR. This mode of operation is paused every 64 seconds for 8 seconds, in order to perform a normal analysis sweep, nominally in SEDDF mode. At this time, the LFDR is also sampled. These provide the low temporal resolution spectrum. At each 64-second interval the millisecond mode frequency is toggled between each of two selections: 2 MHz and 10 MHz. These frequencies could be tweaked with additional commands. WFR data acquisition and Dust detection are not done. Langmuir Probe sweeps are performed every 640 seconds. A Sounder measurement is scheduled every 10 minutes.
It is assumed that prior to this trigger, either trigger A0 (SEDDF) or trigger 8E (Night-Time Survey) was in effect.

Receiver Frequency Range Sensors Time between Snapshots Snapshot Length
LFR 1 - 25 Hz EX, BX 126 seconds
MFDR 70Hz - 1.7KHz EX, BX 126 seconds
MFR 25 - 12 KHz EX, BZ 32 seconds
HFR 3.6 KHz - 16 MHz EX, EW 64 seconds
HFR 2 MHz or 10 MHz band EX 2.5 seconds 2048
WBR 2 MHz or 10 MHz band EX 0.125 second 4096


The HFR is in a modified "Composite Survey" mode, which now includes both auto- and cross-correlations for H1, and differs from standard Survey mode in that its integration constants for H1 and H2 are shorter. 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 64 seconds.