HF data using 3 (maybe more) freq

Comments

• G8JNJ

  August 2018

  Hi Dave,
  
  See
  
  http://forum.kiwisdr.com/discussion/comment/2631#Comment_2631
  
  NVIS makes a real mess of TDoA on the LF bands.
  
  You may have to try TDoA at a few different times if day, before you find stable propagation.
  
  Regards,
  
  Martin

  
• M0TAZ

  August 2018

  Thanks, I think I nailed it now, seems to be on the South coast not too far from Weymouth / Bournemouth area been going all day hopping over 3 freq. TA
• G8JNJ

  August 2018

  Hmmm, not much out that way.
  
  I know St Eval and somewhere in France had been used as test sites, but Blandford and Southwick (Portsmouth) are other possibilities.
  
  Regards,
  
  Martin - G8JNJ
• G8JNJ

  August 2018

  Hi Dave,
  
  I've just managed to perform four runs using different KiWi's (fortunately Emerald was available.
  
  I used the widest I/Q filter bandwidth to straddle two sets of databursts that had no other transmissions at low level in the background.
  
  The best (narrow red band) 'pairs' of plots from all four runs intersect St Eval and the composite best guess location is just off the West Cornish coast in the Irish sea.
  
  Regards,
  
  Martin - G8JNJ

  
• M0TAZ

  August 2018

  Thanks, Martin, very interesting.
• G8JNJ

  August 2018

  Should have said, these are the bursts centered on 4785KHz
  
  See
  
  http://www.hfindustry.com/meetings_presentations/presentation_materials/2017_sep_hfia/presentations/THALES_HFXL_HFIAsept2017_Presentation_final2_Bernier.pdf
  
  Regards,
  
  Martin - G8JNJ

  
• i56578

  January 2019

  hi, take a look here
  https://i56578-swl.blogspot.com/2018/09/psk-8-bursts-at-inconsistent-12800bps_19.html
  http://i56578-swl.blogspot.com/2018/11/8-ary-constellation-bursts-at-12800bps.html
  
  73
  Antonio
• WA2ZKD

  January 2019 edited January 2019

  The Thales scheme is quite different from the MIL-STD, Harris and Rockwell schemes.