Dr. Robert Westphal (aka @RobW) gave a presentation entitled “Geocaching in the Ionosphere” at the international amateur radio scientific workshop HamSCI 2021 held on 19th – 20th March 2021 and hosted by the University of Scranton, Pennsylvania, USA.
The presentation gives an overview of the use of the Weak Signal Propagation Reporting Network (WSPRNet) in the search for MH370. Data have been recorded in the WSPR database (www.wsprnet.org) for the whole flight duration of app. 8 hours with signals from 7 MHz to 28 MHz and stations from Europe, Asia, North and South America as well as Australia and New Zealand. WSPR signals indicate the U-turn at 17:22 h UTC and the Final Major Turn (FMT) heading 180 degrees towards the Indian Ocean at approximately 19 h UTC.
@RobW
An excellent presentation of how the WSPR technology can help the search for MH370. This is still a work in progress, but promises to bring further insights into the MH370 flight path into the Southern Indian Ocean. I am also hopeful that the superDARN technology will add to our overall understanding of the final hours of the MH370 flight and help unravel one of the world’s greatest aviation mysteries.
Quite amazing use of WSPR technology.
@RobW
Rob, I am trying to understand your report that you detected Davis Station helo operations in February this year. I am having difficulty establishing a great circle path from DP0GVN (presumably at or near 70°38′42″S 8°15′51″W) to anywhere in New Zealand that passes within 3800 nautical miles of Davis Station (68°34′36″S 77°58′03″E).
Can you please illustrate the path that you believe that affected signal took between the transmitter and the receiver.
@RobW
Rob, while you’re looking at the Davis Station matter can you also please illustrate the mechanics of your reported detection of Qantas’s Antarctic flight out of Perth on 26 January 2021 (QF2904). In your paper you state that you studied the backscatter effects from 1.500 km south of Perth using JH3APN as the receiving station and VK6CQ as the transmitter.
VK6CQ is in Perth, Australia and JH3APN is in Higashiosaka (Osaka), Japan. After a departure from Perth (that incidentally would have taken the aircraft almost directly over VK6CQ in the suburb of Willetton) QF2904 flew approximately true south to Antarctica. Apart from briefly on departure from and again on approach to Perth I cannot see where QF2904’s flight path intersects either the short or long great circle paths between those two stations you’ve nominated. 1,500 kilometres south of Perth QF2904 is hundreds of kilometres off the long great circle path.
@Mick Gilbert
Thanks for your interest in MH370 and WSPR. Please send me your email address for further communication in detail and your background information. General remarks:
My intention is to increase leverage with regard to MH370 and the attempt regarding “misusing” WSPR for any possible clues or help with regard to MH370.
The rational for the observations from Newzealand to Antarctica was, as follows:
Find less crowded airspace in the Southern hemisphere for the live tests according to
3-step procedure observation – validation – verification. ZL2005SWL is a well suited WSPR receiving station (RX) with good receiving sensitivity and on the air 24/7 which does not apply for all the spotters. Same for DP0GVN in Antarctica as TX. Not too much traffic between them. Now in Antarctic winter less reports and change to lower 7 MHz mainly.
So I started monitoring that link. Whenever I found anomalies I searched the path with FR24 on great circle (VOACAP Hamonline) and surroundings. So the H125 at Davies are offset the theoretical great circle which is not necessarily a surprise. Path with better bouncing? Or two mini great circles between TX – object – RX?
Talking leverage: I am looking for experts to help. If many will interrogate and one person has to respond (Grand Jury?) there will be no leverage but just 24/7 work for one individual. We have the database, the assumptions and the common goal. So I will appreciate if we all collaborate on the data and try to find clues or s.th. better than clues.
QF2904: One of the last RX close to MH370 was VK6ZRY in Perth. He sadly enough deceased in 2017 so we can no longer ask him. That was the rational to look for VK6 stations. JH3APN in Japan was a very busy RX before and after midnight in 2014. That
is the reason I studied JH3APN and any possible influence, such as a spherical triangle JH3APN – MH370 – VK3 or VK6 or VK2 or ZL WSPR stations. Gut feeling, no proof or nice theory for that at the moment.
SuperDARN ZHO showed reflections at 3.500 km at beam 0 towards Cape Leeuwin. Indicated Range is not sufficient, range ambiguity not checked yet on that radar, but data are available (Just google Virginia Tech SuperDARN Chinese RADAR ZHO). Looking for an expert on SuperDARN and HF propagation in and along Aurora Aurealis.
One important question is, if the aircraft has to be within the Baseline of TX and RX. QFA 2904 was outside (South) of this baseline. As long as it was > 1.500 km South of PER I could not see any influence on the WSPR RX signal. Closer than that distance fluctuations started to my surprise. Later I repeated that with a flight PER to HKG (within the baseline), similar result on RX JH3APN. So in general flights heading South to North.
Most interesting is repatriation flight QFA114 in November 2020 from JNB to PER but I do not recall at the moment if JH3APN was involved. QFA114 passed very close to IG’s LEP at 22:48 h UTC. Lots of signals on major circles. Obviously no one looked at these data yet.
So in summary to your questions: I was not searching for great circle paths according to your 2 questions with regard to H125 and QFA2904 but for observation and some form of validation for the VK6 and JH3APN RX contributions in that night in March 2014.
How can we find a procedure to proceed without putting the whole burden on one or two persons?
We can discuss the details “offline”. This procedure was part of the observation and validation part of the 3-step-approach observation- validation – verification.
ZL2005SWL has no live WSPR access so I could not see the raw signals. Live raw WSPR signals have been observed at ZL1PWM (closed down Jan 31, 2021), also monitored aircraft signals over 2.000 km with VK7HH as WSPR TX, being received by ZL1PWM.
For better understanding I encourage everyone interested to study live and raw WSPR signals at some of the 600 global WSPR RX at http://www.kiwisdr.com and the influence of air traffic. The RX are ranked at http://www.kiwisdr.com with regard to their SNR capabilties.
Start with loitering aircrafts and rapid change of heading close to major airports then increase distance as soon as you got practice. Be aware that many influenced raw WSPR signals in amplitude, shape in time and frequency domain will not be decoded and stored in the database http://www.wsprnet.org. You can observe that live at a KiwiSDR in mode WSPR.
Keep ionospheric conditions in mind (www.spaceweather.com). Now we are between peak of solar cycle 24 (04.2014) and 25 (cycle just started), expected peak in 2025. QFA1334 flew PER to PER last weekend but poor HF conditions to Japan, anyway there was VK0PD in WSPR at Casey station Antarctica and a cluster of signals at 10 MHz.
@Mick Gilbert. From Victor’s blog I see you may have missed @Rob’s comment above.
Adding to that, I posed related questions to @Richard, who responded as follows on 3rd March at 11:38 in: https://www.mh370search.com/2021/01/21/mh370-debris-drift-analysis/comment-page-3/#comments .
“You ask: “You note the detection of an SNR anomaly, its drop I take it rather than the scatter, that indicating interference. Thence knowing from ADS-B that there was a helicopter operating at Davis, the coincident timing of that and lack of other candidates, you deduced that side scatter from that was the likely cause of the interference. Is that about right?”. The short answer is yes.
The long answer is that in the case of the H125 helicopters, we think we had no direct link over the pole to DP0GVN (we still have to check SuperDARN data over the pole for flares etc.). The WSPR signal from DP0GVN in Antarctica, assuming an isotropic radiation in all directions, hit the helicopters at Davis and was scattered amongst other directions to ZL2005SWL (-13 dB) in New Zealand. The signal from DP0GVN also went and to a large number of other stations on 27th February 2021 at 08:08 UTC, 08:24 UTC and 08:38 UTC. For example, the WSPR was received at two stations on Maui, Hawaii AI6VN/KH6 (-23 dB) and KH6KR (-11 dB) at 08:24h UTC. Other spots recorded in California K6KR (-11 dB), KFS (-11 dB very strong) and many other directions (mainly USA, 1 Brazil, 1 Oceania). Here is a list of all the WSPR spots:
https://www.dropbox.com/s/6now4aixv6ed5at/WSPR%20Spots%20DP0GVN%2027FEB2021.png?dl=0
You also asked: “in your earlier example you were able to place the source of interference in the line of the transmission, though in retrospect I do not know how you concluded that.” I do not believe that forward, side and back scatter can be used for a precise triangulation, but perhaps to determine a general area of interest. I do not know how best to graphically present isotropic transmissions, multiple receptions and possible scatter from an aircraft. When multiple receiving stations show an anomaly in the Rx SNR at the same point in time, then it may be because of scatter from an aircraft (amongst other possibilities). You can reduce the number of other possibilities by looking at the history and the propagation conditions. When you detect a WSPR anomaly at multiple receiving stations at the same time from an aircraft with a known position from ADS-B data, then you may be able to continue to track that aircraft when the ADS-B data ceases. Similarly if we can detect WSPR anomalies from MH370 early in the flight at known ADS-B locations, we may be able to continue to track MH370 later in the flight. We can then double check any candidate WSPR detection areas against the satellite data.”
Also, if you scroll down farther to 12th March, 11:35, you will find another of @Richard’s posts, related to great circle detection.
While forward and back scatter have received the most attention, it seems possible to me, as a rank amateur, that the strength of side reflection would depend on the aircraft inclination to the transmitter and whether that to the receiver is about the same. Also, with the helicopter’s case there are the rotating blades and their multiple vortices at play.
I for one hope that Richard’s second paper will help clarify this general topic.
@Rob
Thank you for your reply. I’ll look to contact you separately by email. I have no technical background, I am neither an engineer nor or scientist (not in the “hard” sciences, I have a social science qualification) and I have no experience whatsoever in amateur radio.
I can, nevertheless, read and grasp the basics of what’s being proposed. I am always concerned by unconditionally declarative statements based on barely more than speculation. In your paper you stated that helicopters at Davis Station had been detected by ZL2005SWL in New Zealand based on signals received from DP0GVN in Antarctica.
You’ve offered no conclusive proof that that is what occurred. As I understand it there are myriad factors that could have caused the ZL2005SWL data to look that way. Not the least of which, I suspect, is that ZL2005SWL sits adjacent to one of the busiest domestic air routes in New Zealand; Auckland – Christchurch. At the time of the Davis Station helo ops there were numerous commercial aircraft passing adjacent to or over ZL2005SWL. How can you prove that the “detection” related to the Davis Station helos and not a helo flying in Milford Sound in New Zealand or Air New Zealand flight 571 from Auckland to Christchurch passing ZL2005SWL?
You run into the same problem with two of the other stations you have used; VK6CQ in the Perth suburb of Willetton and JH3APN in Higashiosaka, Osaka. They are both close to major airports. In fact for an attempt at studying the detection of aircraft using WSPR you possibly couldn’t have picked a worse station than VK6CQ. Perth has two airports – the main commercial domestic/international airport and Jandakot general aviation airport – and VK6CQ sits between the two. How can you eliminate the influence of aircraft that are close to the station?
I am happy to keep an open mind on this but you and proponents of this approach have a lot of work to do to prove conclusively that it is useful. To say that you have “detected” a specific aircraft you need to be able to eliminate all other potential factors, including other aircraft, from the equation.