H3211 anthea's hf exp 26jul17
h3211 took data on 26jul17 from 14:00 to 16:45 (ast)
using the hf facility and the 430 tx.
to the setup used and hf transmitting sequence.
- Coded long pulse data was taken with the 430 MHz tx
- single beam, gregorian -> usrp datataking system
- baud was 2 usec (300 Meters resolution).
to plots of the hf and 430 tx power
- The heater was run with cycles of:
- 4min hf on , 4 min hf on, then
- 8min hf on , 8 min hf off, and finally
- 2min hf on , 2 min hf off.
- The hf frequency was 5.125 MHz.
- The 430 frequency channel with the peak enhanced plasma line
was 435.1209 MHz
Processing the data:
The data processing was done twice: once with
a 10 second integration, and later part of the data set was
processed at .1 second integration time. The steps for each set
- Decode the coded long pulse data, compute spectra, and then
integrate (to 10 or .1 seconds)
- The baud was 2 usec, we generated spectra at a height
spacing of 1 usec (150 Meters).
- over plotting the data, look for the frequency channel that
had the strongest enhanced plasma line.
- This turned out to be a constant frequency channel for most
of the run.
- The peak was 4.2 Khz below the hf frequency (the freq
resolution was 760Hz)
- We also saw smaller peaks at 2 and 3 times the ion-acoustic
wave freq below the hf freq.
- The freq channel of the peak was extracted for the entire data
set. It was then normalized to its median value (making the
units Tsys .. probably around 120K).
Range vs time for peak enhanced freq channel for entire run.
The first plot shows the range
vs time plot for the peak freq channel (at 10 seconds time
- The horizontal axis is UTC Hour of day for 26jul17
- The vertical axis is range in Km.
- the grey scale i power at the enhanced plasma line peak freq.
- the image has been scaled to 5 sigma on the noise, so the
enhanced plasma line has been saturated.
- The vertical striping is the clutter from the enhanced plasma
- the solid color vertical strips have no 430 data.
- You can see the range vs time for the natural plasma at the
peak freq (5.12085MHz).
- toggling of the hf power:
- the hf was off from 18.3 to 18.583.
|hf on, off cycling
|4 min on, 4 min off
|8 min on, 8 min off
|2 min on , 2 min off
|2 min on, 2 min off
- the data after 20.75 hrs was corrupted by the 430 tx
Blowups of the 8 min hf on sections (10 sec resolution).
The range vs time
for the peak freq channel was plotted for each of the 8
min hf on sections (.ps) (.pdf):
- Each frame is an 8 minute hf on sequence
- The data is integrated to 10 seconds.
- Ranges 200-250 Km are over plotted.
- The dashed red line is an approximation of when the heater was
- page 1:
- top: 8 min on starting at 19.24
- bottom: 8 min on starting at 19.51
- page 2:
- top: 8 min on starting at 19.78
- bottom: 8 min on starting at 20.04
- this is missing the 430 data from the turn on.
- page 3:
- top: 8 min turn on at 20.32
- The maximum turn value was 12000 *Tsys at 19.78.
.1 second time resolution image of the 8 min hf on at 19.78 hrs
an image was made of the 8 minute turn on
at 19.78 hours using .1 second time resolution (.png)
- The image used the frequency channel of the peak enhanced
- The hf turn on occurred around 19.782 hours.
- The vertical striping is the clutter
- the image has been scaled to about 3 sigma on the noise.. so
the enhanced line is saturated.
- The natural plasma line is barely visible in the off period
(it is easier to see in the movie).
.1 sec res, spectra vs range movie
- a movie was made of spectra vs range for the time period
19.7817 thru 19.8174 hrs utc (.avi)
- freq: 435.1 to 435.12 MHz
- range: 219.8 thru 221.4 Km
- time duration: 19.7817 thru 19.8174 Hrs UTC
- The time duration for each frame is .1 seconds.
- Each height spectra in offset vertically from the previous
- The rightmost vertical line is the hf frequency (430 + 5.125
- other vertical lines are spaced by the distance from the hf
Freq to the maximum enhanced plasma line channel.
- this 2nd and third peaks are not multiples of the distance
from the hf to the 1st peak.
- The vertical scale was changed twice during the movie (since
the enhancement was getting weaker)
- This shows that the frequency channel for the peak
enhancement stays within about 1 freq channel (700hz) during
Over plotting the peak freq channel vs range and time for 8
Using the peak freq channel, the
ranges 216.5 thru 221.0 km were over plotted for the 8 minute on
- The time resolution is .1 seconds.
- The vertical scale is in units of Tsys. The max value is
37,000 * Tsys.
- The bottom plot adds a display offset to each height. The
enhancement is moving down in range as time goes on.
Over plotting the peak freq chan vs range for the 1st 23 seconds
the peak freq channel is plotted range vs time for 23
seconds around the turn on at 19.78 Hours (.ps) (.pdf)
- ranges 220.4 thru 221.75 are over plotted.
- The hf is turned on somewhere around 3 seconds
- The maximum value is in range 220.85. It gets to about 37000 *
- The large turn on lasts for up to 10 to 15 seconds.
- The bottom plot includes a display offset to separate out each