Setup:

• The experiment was done at 5.125 Mhz using the 3 tangential antennas. We had trouble with tx 5 so we ended up using:
• tx1 -> Dipole 1A
• tx3 -> dipole 3A
• tx6 ->  dipole 5a.  We added a 14.5 ft length of coax to get from tx 5 to tx6.
• Dana corrected for this with the transmitted phase
• We drove each antenna with about 58 KW.
• dana setup the drive signals to generate either of two circulars
• We started with what he thought was the correct circular. I've called this pol1 in the table below.
  

Acquiring the data

• pol1 is the pol we started with. Dana  claims this is the correct pol
• pol2 is the other circular polarization.
• The switches were made by mike sulzer talking to dana over the phone to "switch now". I was trying to write these times down as they happened.
• looking at some of the total power plots, it looks like some of the times were recorded were not correct (signal appears when hf off).
  

movies of decoded data

    I used the standard plasma line processing to generate a movie with 1 and 10 second integrations.

• This processing removes the spectral baseline with a 96 khz median filter. This will smear out broad features.
• The movie dynamic was probably scaled to 3 sigma on the noise.
• This allows us to see the regular plasma line
• it completely saturates the strong echoes.
• We got a return at 109 Km. We did not resolve it in range (300m) using the 2usec baud.
• 
  
• movie with 10 second integration (.avi for linux)   (.mov .. quicktime format)
• movie with 1 second integration (avi for linux)  (.mov  quicktime format)

Total pwr in range vs time

• This is before decoding so any strong returns will be smeared over the 440usec pulse width (66 km)
• I kept 100 to 200 Km.
• a bandpass correction was done using 190-200km averaged over each file.
• There at 109 secs in each file, (10900 10 ms ipps)
• To get the image to fit on the display:
• i averaged in range from .2 to 1 usec
• i averaged in time (ipps) 7 ipps (to 70 ms)
• During a polarization switch, we were probably not transmitting a pure circular, (changed the phase of 1 dipole at a time).
  
• Images were made with:
• scaling [-2,+5] sigma on the noise.. to see weak stuff
• scaling [-2,+50] sigma .. to make the strong stuff stand out.
• At the bottom of each image, colored bars show when transitionss occurred.
• HF turned off
• HF turned on, using pol 1
• HF turned on, using pol 2
• looks like we were off with some of the recorded times
• The title of each image contains the start time (ast) as well as the state of hf xmiter when the file started.

• The strongest echo  in file 2  (at 2.67 seconds) was seen in only 1 ipp (10 ms ipps)
• Page 1 plots total power in each sample (no decoding) vs range (km).
  
• Page 2 plots total power in each sample (no decoding) vs time usecs from rf pulse.
• The top frame shows 90 to 180 km (600 to 1200  usecs)
• the middle frame shows the start of the return echo
• the bottom frame shows the end of the strong return echo.
• the red line is the duration of the pulse.
• the strong echo was not resolved by the pulse.
• The blue and green lines show the previous and next ipps ,.

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