tl;dr Why was passive radar not employed to determine the ultimate path of MH370 to refine the search area?

And do the advances in AI make this technology more relevant, perhaps down to the point where AI could be employed to track almost any movement in the air (and potentially on the ground)?

Figured this was more of a technology related question than history or politics, but I wanted to see if our Aggie braintrust had any insights on the following question.

Watching Air Disasters yesterday on the episode covering the 1983 tragedy involving the Russians shooting down Korean Airlines 007. I remember when it happened despite being a small child and again when the black boxes were handed over to NTSB at the end of the Cold War.

What I was NOT familiar with was that the US knew within hours of the plane going missing. They mentioned the US military had "advanced technologies" that were listening to Russian military comms as part of their knowledge.

Then somewhat later they mentioned the US had employed "passive radar" to determine the route of the plane and that it was classified at the time to how it works. Move forward 30 years later and I do not recall hearing much of anything about this technology, which should have advanced tremendously over those 30 years, being used.

Its been bugging at me that perhaps it remains classified to a large extent. Or maybe the proliferation of flying objects make it harder to use - though GPS signals, satellite radio and even HD tv signals (in the US particularly) combined with computing power should make it viable.

Below is some reference material. Appreciate any thoughts, insight and equally appreciate if someone yes "you dolt, you have no clue what you are talking about".

https://www.airlineratings.com/articles/mh370-ground-breaking-report-reveals-location

https://spectrum.ieee.org/passive-radar-with-sdr

Passive radar is just turning your radar reciever on and listening to the returns of local radio towers and other 'illumination' sources rather than turning on a big spot light of a radio beam from your own radar dish.

For 370 there likely were no radar receivers in the area to passively observe the plane let alone any large civilian radio sources to illuminate it.

What did you think of the findings from the first link?

And did USA just get lucky in 1983 "guessing" the route and referring to passive radar at some point that it gets included years later on Canadian TV?

BTW, brought this up to a buddy who happened to spend a bit of time as a boy in S Korea, he was unabashed that we probably had spy tech on the KAL flight.

Edit to add: not trying to be argumentative at all, just really trying to understand this.

Until flight 370 is located, this is probably just another theory to put on the pile of theories. Albeit this one is a bit more compelling if for no other reason than the fact that all the theories that came before this one have failed to reveal the location of the plane.

I've read about their efforts a couple years ago and while it looks compelling, it's a new technology being used in a novel way to look for a specific aircraft. Had this technology been developed prior to 370 and had previously proven the ability to track known aircraft, it would be for more credible.

On a side note, software defined radios (SDR) like the ones that produced the recordings they used in their analysis are fun to play with. In addition to being able to listen to specific frequencies, you can view spectrum graphs showing the strength and modulation of the signals received across wide frequency bands.

During the early hours of Russia's invasion of Ukraine, I logged into several of the SDRs in the region to watch what frequencies Russia was jamming and where they were jamming them.

Thanks for feedback. One of my biggest questions is that it is not necessarily new technology. As mentioned in the OP, it evidently helped locate Korean Air Lines 007 back in 1983.

Just not adding up for me.

Passive radar is different from what they're doing. Passive radar is taking a regular radar and putting it into listen mode without turning on the transmitter. You're listening for other radar or even AM or FM radio waves being reflected off the aircraft.

This new analysis is taking many civilian ham radio recordings and basically overlaying them to determine why some stations receive a delayed or weaker signal than other stations.

The first example is a direct observation of a reflected signal off a plane. It's probably been in use since the 50s when trying to hide the location of front line radar sites by using other more distant radars to illuminate the target aircraft.

The second technique was probably developed in the 90s for militaries to 'track' stealth aircraft like the downed F-117. This newer analysis is cobbled together using ham radio recording made on a PC in a hobbyist's home and is a pretty unique use of open source data.

Diego Garcia?

Plus Australia has long been littered with listening stations to support the space programs.

Just seems like there is oddly little information on the progress of a technology that provided real-time flight tracking in 1983.

This. The airspace around Alaska and over toward Russia is and was some of the most heavily surveilled space in the world. Has a ton of high powered early warning radars that blast energy 24/7 watching for incoming missile threats, etc.
Where MH370 disappeared... not so much.

Also of note, even before this latest analysis, early on they looked at records of Inmarsat transmissions from the aircraft and did a very rough TDOA (time difference of arrival) analysis between two different satellites to at least attempt to figure out a most likely flight path. Believe the data was very inconclusive still.

flown-the-coop said:

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Diego Garcia?

Plus Australia has long been littered with listening stations to support the space programs.

Just seems like there is oddly little information on the progress of a technology that provided real-time flight tracking in 1983.

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Different frequency bands and receiver types in play. Plus, ground stations used for space tracking and space comms are engineered to reject as much "clutter" from nearby ground and air traffic sources as possible. The space stuff essentially has blinders on.

The KAL shootdown was mistaken identity but in that case you still had an aircraft with a functional transponder, squawking codes that numerous ground radar sites were able to pick up, not to mention USAF surveillance platforms in the area that were flying their normal missions.

Appreciate the responses. My questions are keenly around passive radar and why is it not more refined, advanced 40 years after it was used to track KAL 007.

Also, Russians probably had reason to shoot down the plane as there is strong likelihood it was surveilling the Russians though it getting off course allowed the Russians the international excuse to take it down.

You can make a passive radar listening device and put it in your backyard. Hooking it into an high powered computer or better yet an AI solution and it would seem to have some capabilities.

My gut tells me we have long had this and likely had much more information on the location of MH370. Was it simply not revealed as there was no reason to reveal it?

Remember, with passive radar it is just listening and does not transmit its own signals.

It is certainly more refined, at least in terms of the algorithms and ability to prosecute signals that 40 years ago would have been considered "down in the noise." But, at the end of the day, it turns into a physics problem. MH370 was flying in an area without a high concentration of large radars or sensitive receivers which could have taken advantage of passive radar techniques. No ears listening, effectively.

Makes sense. And true too that there would be a lack of signals in the area for a passive radar to "listen" to given the remoteness.

Appreciate you guys humoring me. Seems like Stalink and similar should make craft being able to disappear be somewhat a thing of the past.