Trigger 94 Description
Sequence: C27
Trigger 94 ( Aurora/SKR Mode, outside source crossing & low latitudes )
This mode is designed to provide a survey mode with full direction-finding (DF-3)
up to 1.8 MHz.
Both low and high frequency WFR measurements are made. In high-frequency
mode, there are 512 samples taken for the EX, EW, and BX antennas. These
channels are also analyzed onboard using the LFDR FFT software, and the
LFDR data is provided in addition to the waveform data. In low-frequency
mode, 5-channel 1024-sample WFR measurements are made every 64 seconds.
Langmuir Probe sweeps are performed every 32 seconds; density measurements
are made at a 100-Hz sampling rate to match the Low-Frequency WFR measurements.
A simple up-going ramp sweep is performed; with a future software update,
this will become a down-going voltage ramp.
A Sounder measurement replaces the HFR data every 320 seconds.
| Receiver |
Frequency Range |
Sensors |
Time between Snapshots |
| LFR |
0.1 - 2.5 KHz |
EX, EW, BX |
32 seconds |
| MFR |
25 - 12 KHz |
EZ, BZ |
32 seconds |
| WFR(LF) |
1 - 25 Hz |
EX,EW,BX,BY,BZ |
64 seconds |
| WFR(HF) |
0.1 - 2.5 KHz |
EX,EW,BX |
32 seconds |
| HFR |
3.6 KHz - 16 MHz |
EU, EV, EW, EX |
32 seconds |
| LP |
N/A |
Langmuir Probe |
32 seconds |
| Sounder |
3.6 - 115 KHz |
EX, EW |
320 seconds |
The HFR is in direction-finding mode for bands A, B, C, and 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 8 y 1000 1 3.6-319 kHz
H1 2E y y 1 y 80 1 60 25 325kHz-1.8MHz
H2 1E n n 1 n 20 1 72 50 1.8kHz-16MHz
Bands ABC require 6.42 sec to complete, H1 requires 10.31 sec, and H2 requires 1.46 sec
for a total of 18.19 sec per sweep. However, the time between analyses is set to 32
seconds, in order to reduce interference due to antenna-switching done during the
direction-finding measurements.
Every 320 seconds the HFR normal analyses are replaced by a Sounder analysis.
The Sounder operation has a duration of approximately 40 seconds.
This Sounder analysis is defined by:
sounder mode: EZ AAA
1st sounder freq: 0
last sounder freq: 89
T1 delay: 10 msec
T2 delay: 25 msec
T3 delay: 25 msec
passive spectra: 2
active spectra: 2
# of cycles: 1
sounder output A: 3 autos
sounder output B: 3 AGCs