WSPRNet used in the search for MH370?

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Sterling Mann

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May 5, 2021, 1:39:02 PM5/5/21
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This paper by Robert Godfrey [0] seems to build off of the work by Dr. Robert Westphal DJ4FF, who showcased using WSPRnet data to detect aircraft with forward and backscatter in this year's Hamsci conference [1].

Godfrey's analysis is getting a LOT of eyeballs from mainstream media [2] since it extends and validates the path of the MH370 and makes a number of assumptions about the pilot's intentions that are "confirmed" by the data, but it's met with lots of criticism from technical circles. Hackernews has a good thread of critical, civil comments from other hams, engineers, and RF experts. [3]

I share some skepticism; to me there isn't enough evidence to support the claim that air traffic can be reliably geo-located through detection of minute changes to the signal strengths and drifts of WSPR beacons over many-thousand mile long paths (and long path even) due to variabilities in the ionosphere and ground conductivity, the antenna of each station, their power output, among many other things. I am well-versed in bi-static radar theory, and Dr. Westphal's research is an analysis of scatter caused by aircraft makes sense, but this isn't adding up in my head. Seems like Mr. Godfrey is basing the geolocation on RSSI deviation from expectation by path loss between TX and RX, making comparisons to "tripwires." That's not quite how I understand HF propagation.

If this is true, it's got some pretty big implications.

I've searched our group and it doesn't seem like this topic came up. Wonder if anyone else is scratching their heads.

[0] https://www.dropbox.com/s/w43gu64vn7jvmxm/Using%20the%20WSPRnet%20and%20Inmarsat%20Satellite%20data%20in%20the%20search%20for%20MH370.pdf?dl=0
[1] https://hamsci2021-uscranton.ipostersessions.com/?s=EA-94-A8-65-0F-B4-9E-48-AF-86-00-56-1C-28-35-64
[2] https://www.airlineratings.com/news/mh370-pilot-made-many-turns-speed-changes-new-report-reveals/
[3] https://news.ycombinator.com/item?id=27044995

73,
Sterling Mann, N0SSC

Phil Erickson

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May 5, 2021, 5:12:18 PM5/5/21
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Hi Sterling,

  The study leaves me insufficient information to reject the null hypothesis and therefore I have concluded that nothing has really been proven.  Ionospheric electron density variability is 1 to 10% on even the quietest of geomagnetic days due to lower atmosphere forcing from things like atmospheric gravity wave propagation.  That variability is not factored into this study, which I'm pretty sure uses a ray propagation tool through a model ionosphere that is a monthly median, heavily smoothed analysis (e.g. IRI).

  There are way too many uncontrolled variables here to make the kinds of associations the study does.  I agree with a lot of the comments in your [3] reference.  Wish it were true, but the Godfrey conclusion has not been conclusively proven until it is independently replicated by another group with enough regression test cases to reject the null hypothesis.  (The fact the software is not available is a BIG problem.)

73
Phil W1PJE


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Bob McGwier

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May 10, 2021, 3:21:18 PM5/10/21
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I concur with Phil 100%.

To view this discussion on the web visit https://groups.google.com/d/msgid/hamsci/CAAZaqEutSUSf9X2GdLrUuz2V3GcEp_Zzx6amXd_Db1sgfAVmHQ%40mail.gmail.com.

Don Westacott

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May 10, 2021, 3:56:33 PM5/10/21
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HamSCi Group

 

“Incredible Claims Require Incredible Data”  Dr. Edward Tufte, professor emeritus of political science, statistics, and computer science at Yale University.

 

I have reviewed Dr. Robert Westphal, DJ4FF, technical presentation and have a number of questions & concerns which likely follow others reviewing this work.

 

Importantly, I cannot immediately dismiss this work, as I suggest this would be inappropriate and evidence does not currently exist within my knowledge base to reach any definitive conclusion.

 

Phil, I strongly agree with your comment ” “way too many uncontrolled variables here to make the kinds of associations the study does “

 

However, I will keep an open mind and gain further data, if possible.

 Science  has demonstrated on may occasions, that events at first termed to be highly improbable or near impossible are changed through understanding to become facts.

 

Don Westacott KI5KGX

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Bob Gerzoff

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May 14, 2021, 8:59:34 AM5/14/21
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I am looking at paired WSPR observations within 2-minute intervals, i.e., sequential observations between the same pair of stations.  I have two years of data but would love to expand the time series.  Would Arne’s Clickhouse database be a potential source I could use?  I can manipulate the raw data if I can get it.

 

73,

Bob, WK2Y

 

From: 'Gwyn Griffiths' via HamSCI <ham...@googlegroups.com>
Sent: Tuesday, May 11, 2021 6:31 AM
To: HamSCI <ham...@googlegroups.com>
Subject: [HamSCI] Re: WSPRNet used in the search for MH370?

 

For anyone interested in looking at the WSPR data covering this period Arne's Clickhouse database has all WSPR spots since 2008.

Phil VK7JJ has a splendid access and mapping interface to this Clickhouse database at http://wspr.rocks/

It will return data in a few seconds or less.

 

For example, set the band as 20 m, the Tx call to VK3DXE and then click the Advanced Search option, in the text box enter

and time > '2014-03-07 21:00:00'
and time < '2014-03-07 21:30:00'

to see just how many other paths there were from VK3DXE in addition to the one identified to 4X1RF, and to see the other paths that had drifts of -2  etc. etc.

 

73

Gwyn Griffiths  G3ZIL

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Gwyn Griffiths

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May 14, 2021, 9:15:58 AM5/14/21
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Bob
Arne's Clickhouse database is certainly a possibility - if you can craft an SQL query to return the spots you need.

See https://wspr.live/ for details of how to access, including via the Clickhouse dialect of SQL, and via that dialect of SQL within Javascript or Python programs.

73
Gwyn G3ZIL

Bob Gerzoff

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May 25, 2021, 11:20:52 AM5/25/21
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I had a question about whether the SQL used by this DB supported the lag function and per the DB home page, emailed ad...@wsprlive.com. Unfortunately, the message bounced.  Does any have Arne’s email or his call sign?

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Gwyn Griffiths

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May 25, 2021, 12:40:44 PM5/25/21
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Bob
Arne's preferred email regarding his database seems to be     admin at wspr.live  no need for .com, the .live being the top level domain.
73
Gwyn

Bob Gerzoff

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May 25, 2021, 12:43:08 PM5/25/21
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Ah that was my mistake.  I just got a quick reply back from him, but I’ll keep this in mind if questions come up down the line.

 

Thanks and 73.

Bob Gerzoff

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May 28, 2021, 8:08:35 AM5/28/21
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Thanks.

 

From: 'Gwyn Griffiths' via HamSCI <ham...@googlegroups.com>
Sent: Tuesday, May 25, 2021 11:25 AM
To: HamSCI <ham...@googlegroups.com>
Subject: Re: [HamSCI] Re: WSPRNet used in the search for MH370?

 

Bob, 

Arne can be contacted at ad...@fggs.de

73

Gwyn G3ZIL

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