If they can detect the faint signal of a heartbeat from so far away, why not instead deliberately transmit a weak, wider-bandwidth pseudorandom magnetic signal? Such a signal would be even harder to detect than a heartbeat without prior knowledge, yet easier to identify and track using a matched filter.
They want to lie about how they found the soldier, and potentially have China spend a few billion trying to copy technology that can never work.
Was there even a soldier to find? Why wasn't his name released? Iran says it was actually a failed operation to capture their uranium.
Militaries and their disinformation units are like this.
There are at least 5 different narratives about how the US found Osama bin Laden, which contradict each other:
https://en.wikipedia.org/wiki/Killing_of_Osama_bin_Laden#Alt...
When a military achieves something and there's intense speculation on how they did it, they will want to obfuscate how they did it. One of the best ways to do that is to give a range of different explanations, some fanciful, some plausible, none of which are completely accurate, leaked to a range of credible and non-credible people. A disinformation campaign.
Why are we assuming China is too gullible to know this technology can never work, when it's so obvious to the lay HN commentariat?
Presumably we're cunningly exploiting specifics of their world view.
Despite the authoritarian rule, PRC still values education highly in quite a few contexts where it doesn't interfere too much with the authoritarianism, and the country not only has plenty of physics graduates who will have learned about the Josephson effect, but might well listen to them and give them adequate grants for R&D.
It's hard for people to imagine someone can be smarter than they are.
Because not everyone has a transmitter, but everyone has a heartbeat?
Though in this case the pilot likely had a transmitter and that's exactly how they found him.