{"id":215,"date":"2017-08-30T23:55:30","date_gmt":"2017-08-30T23:55:30","guid":{"rendered":"https:\/\/geekblog.febo.com\/wp\/?p=215"},"modified":"2017-08-31T17:11:19","modified_gmt":"2017-08-31T17:11:19","slug":"more-solar-eclipse-analysis-hf-propagation","status":"publish","type":"post","link":"https:\/\/blog.febo.com\/?p=215","title":{"rendered":"More Solar Eclipse Analysis (HF Propagation)"},"content":{"rendered":"<p>I&#8217;ve continued processing the data generated from software-defined-radio recordings I made during the 2017 solar eclipse at my fairly isolated and low-RF-noise location on Beaver Island, Michigan (45 38 38 N, 85 29 24 W, grid square EN75gp).  The nearest AM station is about 28 miles away, so it&#8217;s a pretty good site for monitoring the high frequency bands.  The data was recorded over the eight hours from 1400 &#8211; 2200 UTC (10AM to 6PM EDT) on Monday, August 21, 2017.<\/p>\n<p>I&#8217;ve now made movies of my 80M, 40M, 30M, and 20M ham band recordings, using similar methodology to that used for my <A HREF=\"https:\/\/blog.febo.com\/?p=202\">movie of the AM broadcast band<\/A> shown in my prior post, and uploaded them to YouTube:<\/p>\n<blockquote><p>\n<B><br \/>\n<UL><br \/>\n<LI><A HREF=\"https:\/\/youtu.be\/GtPiAjpgHac\">80M Playback (~3 minutes) https:\/\/youtu.be\/GtPiAjpgHac<\/A><br \/>\n<LI><A HREF=\"https:\/\/youtu.be\/Bgvz9Wk9cUM\">40M Playback (~3 minutes) https:\/\/youtu.be\/Bgvz9Wk9cUM<\/A><br \/>\n<LI><A HREF=\"https:\/\/youtu.be\/OAxZmbrNQMM\">30M Playback (~3 minutes) https:\/\/youtu.be\/OAxZmbrNQMM<\/A><br \/>\n<LI><A HREF=\"https:\/\/youtu.be\/7FzoL4jitNs\">20M Playback (~3 minutes) https:\/\/youtu.be\/7FzoL4jitNs<\/A><br \/>\n<\/UL><br \/>\n<\/B><br \/>\n<\/BLOCKQUOTE><\/p>\n<p>Here&#8217;s a randomly chosen frame from the 80 meter recording, captured during the eclipse period:<\/p>\n<p><CENTER><br \/>\n<a href=\"http:\/\/blog.febo.com\/wp-content\/uploads\/2017\/08\/02973.png\" data-rel=\"penci-gallery-image-content\" ><img decoding=\"async\" src=\"http:\/\/blog.febo.com\/wp-content\/uploads\/2017\/08\/02973-300x169.png\" alt=\"02973\" width=\"300\" height=\"169\" class=\"aligncenter size-medium wp-image-227\" srcset=\"https:\/\/blog.febo.com\/wp-content\/uploads\/2017\/08\/02973-300x169.png 300w, https:\/\/blog.febo.com\/wp-content\/uploads\/2017\/08\/02973-1024x576.png 1024w, https:\/\/blog.febo.com\/wp-content\/uploads\/2017\/08\/02973.png 1280w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><br \/>\n<\/CENTER><\/p>\n<p>I haven&#8217;t had time to review these in any detail, but there&#8217;s a noticeable increase in activity on at least the 80 meter recording at around the time of the eclipse.  I suspect there are some very interesting findings in this data, and I&#8217;ll be doing much more analysis.<\/p>\n<p>The hardware used to create the recordings was an <A HREF=\"https:\/\/openhpsdr.org\/hermes.php\">HPSDR &#8220;Hermes&#8221;<\/A> software defined radio with a 43 foot vertical antenna.  The radio&#8217;s amplitude response (reported signal strength at the antenna terminal in dBm) has been <A HREF=\"https:\/\/blog.febo.com\/?p=189\">characterized<\/A> and the results are well within 1.0 dB.   The radio&#8217;s frequency reference was an FTS-4100 cesium standard <A HREF=\"https:\/\/blog.febo.com\/?p=196\">that&#8217;s known to be within 1<sup>-12<\/sup> of the correct frequency<\/A>.  The very accurate and stable frequency reference means that we can extract frequency, as well as amplitude, data from this data.<\/p>\n<p>A Gnuradio script using the <A HREF=\"https:\/\/github.com\/Tom-McDermott\/gr-hpsdr\">gr-hpsdr<\/A> module written by Tom McDermott, N5EG, recorded IQ data from the Hermes receiver during the eclipse, extracting four &#8220;virtual&#8221; receivers tuned to respectively to the 80M, 40M, 30M, and 20M ham bands, each at 384 ksamples\/second.  The data was saved in the HDF5 file format using Gnuradio blocks from the <A HREF=\"http:\/\/www.haystack.mit.edu\/\">MIT Haystack Observatory<\/A> <A HREF=\"https:\/\/github.com\/MITHaystack\/digital_rf\">Digital RF<\/A> package.<\/p>\n<p>To make these movies, I played back the data (about 90 GB per virtual receiver) using another Gnuradio script, and took a screenshot of the FFT (spectrum analyzer) display every 5 seconds.  I converted the ~5800 shots from each band into an MP4 movie at 30 frames per second.  The result is a time-lapse video about 3 minutes long showing activity on that band over the 8 hour period.<\/p>\n<p>The flowgraphs used both for receiving and playback, and several shell scripts I wrote to handle the screenshots and mp4 generation, are available in the &#8220;eclipse2017_playback&#8221; and &#8220;hpsdr_multirx&#8221; repositories at <A HREF=\"https:\/\/github.com\/TAPR\">https:\/\/github.com\/TAPR<\/A>.  I&#8217;m happy to share the raw data, but you&#8217;ll need to send me a 1 TB disk!<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I&#8217;ve continued processing the data generated from software-defined-radio recordings I made during the 2017 solar eclipse at my fairly isolated and low-RF-noise location on Beaver Island, Michigan (45 38 38&hellip;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_lmt_disableupdate":"","_lmt_disable":"","ngg_post_thumbnail":0,"footnotes":""},"categories":[4,9,27,7,2],"tags":[26,25,12],"class_list":["post-215","post","type-post","status-publish","format-standard","hentry","category-ham-radio","category-sdr","category-solar-eclipse","category-test-and-lab-equipment","category-time-and-frequency","tag-beaver-island","tag-eclipse","tag-sdr"],"_links":{"self":[{"href":"https:\/\/blog.febo.com\/index.php?rest_route=\/wp\/v2\/posts\/215","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.febo.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.febo.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.febo.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.febo.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=215"}],"version-history":[{"count":16,"href":"https:\/\/blog.febo.com\/index.php?rest_route=\/wp\/v2\/posts\/215\/revisions"}],"predecessor-version":[{"id":241,"href":"https:\/\/blog.febo.com\/index.php?rest_route=\/wp\/v2\/posts\/215\/revisions\/241"}],"wp:attachment":[{"href":"https:\/\/blog.febo.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=215"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.febo.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=215"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.febo.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=215"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}