PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2005-11-29 NOTE = " S14_TRIG_A6.TXT describes the RPWS instrument configuration for the High Frequency Receiver (HFR), the Medium Frequency Receiver (MFR), the Low Frequency Receiver (LFR), the Waveform Receiver (WFR), the Wideband Receiver (WBR), the Langmuir Probe (LP), the Sounder, and the onboard Dust detection algorithm when using Trigger A6." END_OBJECT = TEXT END Trigger A6 Description Sequence: C37 Trigger A6 ( MAG BOUNDARY(max) ) This mode assumes a background survey mode, such as 8A or 8E, is running, and on top of that overlays fast WFR data acquisition. In order to do this, the LFR data acquisition is changed from its default of toggle mode to Hiband-only. This provides the MFR-2 replacement data. The WFR is run in LoBand-only mode. The 1-10Hz LFR data 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, giving almost continuous coverage. In addition to limiting the LFR 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 6000 bps. During C37, in a short test, the measured bit rate was 5500 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 MFDR 200 - 1400 Hz EX, BX 48 seconds WFR 1 - 25 Hz EX,EW,BX,BY,BZ 24 seconds HFR 3.6 KHz - 16 MHz EX, EW 16 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 32 n 1000 1 3.6-319KHz HF1 2E y y 2 n 80 1 60 25 0.325-1.825MHz HF2 1E n n 1 n 40 1 143 100 1.825-16.125MHz Bands ABC require 3.120 sec to complete, H1 requires 5.473 sec, and H2 requires 5.034 sec for a total of 13.626 sec per sweep. The hfr cycle time is 16.000 seconds. However, the time between analyses is set to 16 seconds to reduce the bit rate. 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