13jun16 hf 3sec on,off and 10ms resolution
campaign on 10-14jun19 synchronized the hf and 430
transmitters to the hardware 1 second tick.
On 13jun19 13:45 to 18:00 (AST) project H3368 did:
- hf tx at 5.125 MHz
- 3 second on (L=0) .. rcp
- 3 second (L=1) .. this was the off.
- start at 13:46:00 ast with a 3 second on.
- The 430 transmitter ran clp with a 440 usec rfpulse and a 10
The normal plasma line processing was to do 10
second integrations, synchronizing these with the hf on and offs.
Looking at high time resolution.
The data was reprocessed using 10ms resolution
for the spectra and then movies were made.
The movie parameters were:
- Start time: 17:06:36 (AST). this is the start of an on
- End time : 17:10:00 (AST) . end of an off.
- During this time we had Fregion and Eregion enhanced plasma
- Freq plotted:
- 435.083 to 435.160 MHz (101 channels with 763Hz resolution).
- Heights plotted
- Fregion: 232.75 to 234.25 Km (.15 km resolution.. which over
sampled the 2usec baud)
- Eregion: 109.75 to 111.25 Km
- Times plotted
- There are 100 ipps/second
- The hf used a 3 second on , 3sec off cycle
- 300 ipps on followed by 300 ipps off
- I plotted 10 ipps (.1 seconds) before and after each second
spectra line movie shows the E and F region data at 10ms
resolution (.avi) (.mov)
- Top Frame: F-region enhanced plasma line
- Bottom Frame: E-region enhance plasma line
- title labels:
- ippInCyle: this goes 1-600. 1-300 is the on, 301 to 600 is
- cycleTm: on/off + secs .. this tells the start time
offset for this ipp in the on or the off.
- Vertical lines:
- plotted mainly as a frequency reference.
- White: the hf frequency of 5.125 MHz
- Red: offset from hf Freq to the F-region enhanced
plasma line (3.1Khz ..which i got from one of the stronger
- I plotted 3 of these offsets
- The vertical lines were plotted for the F and E region plots
so you can compare the locations of the enhancements).
line movie shows the E,F region with a 10 second
integration (.avi) (.mov)
This is a section of the standard plasma line
When do the enhancements occur:
There is a bit of a race condition when going
from off to on and on to off
- On to Off transition
- We still see an enhancement on the first ipp of the off.
- This could be showing how long the instabilities take to
decay .. but:
- The leading edge of the 430 Off rf pulse is only useconds
behind the trailing edge of the hf 3 second on pulse
- We haven't taken into account any differential delays in
the 2 transmitters reaching the center of curvature of the
- There could also be a differential velocity for the two freq
(5 and 430 MHz) as they approach the reflection height.
- Off to On transition.
- The hf 3 sec pulse leaves the hf signal generator on the
- It then has to go through the hf transmitter, the heliax
to the dish, and out the dipoles
- The 430 rf pulse leaves the signal generator probably
12 usecs after the 1 second tick
- We rarely see an enhancement in the F-region on the first on
- We do see enhancements in the E-region during the
first on ipp.