Trigger 10 Description
Sequence: C2 (Antenna Deployment)
Trigger 10 (Sounder and Langmuir Probe Checkout)
This mode is part of the antenna deployment checkout. It runs a series of checkouts internal to the instrument.
It starts with one HFR Sounder pulse in default mode and then it does a Langmuir Probe checkout.
This trigger lasts for about 5 minutes. After the Sounder test, the HFR is in its default mode.
After the Langmuir Probe checkout ends, the instrument internally executes Trigger 30. LFR,
MFR, WBR and WFR data are collected during this trigger, with the receivers connected to
the Langmuir Probe and the individual cylinders when appropriate. The internal sequence of this trigger is:
Operation Duration
------------------------- ----------
HFR Sounder 12 seconds
Ex- Cylinder Bias -13 V 32 seconds
Ex- Cylinder Bias 0 V 32 seconds
Ex- Cylinder Bias +13 V 32 seconds
Ex+ Cylinder Bias -13 V 32 seconds
Ex+ Cylinder Bias 0 V 32 seconds
Ex+ Cylinder Bias +13 V 32 seconds
LP Sphere Checkout 96 seconds
Enter Trigger 30 Mode
During the initial inflight use of Trigger 10, 20, and 30 (during the
antenna deployment in C2), the HFR did NOT go into the expected mode due
to a software feature between the HFR and the order that the HFR commands
were issued from the onboard sequence and the IEB (see ISA Z44412 for a
discussion of this issue and the solutions implemented to prevent this from
occurring in future sequences.
This problem only occurred during the antenna deployment sequence, and not when the Triggers were sent individually.
Comments have been added to the C2 timeline to note which periods had Triggers that did not operate as expected.
The primary affect of this problem was that Trigger 30
did NOT put the HFR in the expected mode at the end of
Trigger 10 and 20 (the HFR stayed, or entered its default mode).
Furthermore, for the first two uses of Trigger 20 (1997-298T00:15
and 03:38), the HFR collected no data during
the internal Antenna checkout part of the trigger, resulting in no HFR data for
about five minutes.
| Receiver |
Frequency Range |
Sensors |
Time between Snapshots |
| LFR |
1 - 25 Hz |
EW, BX
|
16 seconds |
| MFR |
25 - 12 kHz |
EX, EW
|
32 seconds |
| WFR |
.1 - 2.5 kHz |
EU, EV, LP, BY, BZ |
16 seconds |
WBR
|
0.1 - 10.5 kHz
|
LP |
8 seconds
|
| HFR |
3.6 KHz - 16 MHz |
EX, EW
|
24 seconds |
LP
|
N/A
|
Langmuir Probe
|
16 seconds
|
| SOUNDER |
3.6 - 115 KHz |
EW |
N/A
|
The HFR is in the following 'default' mode after the initial Sounder checkout.
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 3.6-319 kHz
H1 2E y y 4 n 160 1 70 25 250k-1.975MHz
H2 2E y y 1 n 80 1 70 200 2.025M-15.825MHz
Bands ABC require 3.12 sec to complete, H1 requires 12.30 sec, and H2 requires 6.27 sec
for a total of about 21.7 sec per sweep. However, the time between analyses is set to 24 seconds.
The Sounder operation has a duration of approximately 12 seconds. This Sounder analysis is
defined by:
sounder mode: EZ AAA
1st sounder freq: 0
last sounder freq: 89
T1 delay: 5 msec
T2 delay: 5 msec
T3 delay: 5 msec
passive spectra: 0
active spectra: 1
# of cycles: 1
sounder output A: 3 autos
sounder output B: 3 AGCs