France's aircraft carrier located in real time by Le Monde through fitness app

Post by mrguyorama » Fri, Mar 20, 2026, 7:53 PM UTC

Sanzig wrote: post #202

throwaway894345 wrote: post #177

Earlier quoted context omitted.

How do these work? I would think radar would have a very difficult time seeing a ship against the backdrop of the ocean from so high above. Is the satellite bouncing radar waves off the side of the ship as the satellite is near the horizon? Even if you can detect a ship, I'm having a hard time imagining a sufficiently high radar resolution for such a wide sensor swath width at such an extreme range. Is the idea that…

SAR operates in side-looking slant geometry. Consider shooting a ray at the ocean at an oblique angle from a satellite: it bounces off and scatters away from you. Hardly any of the energy scatters back towards you. Now, put a ship there. The ray bounces off the surface of the ocean and scatters up into the side of the ship, and from geometry, it's going to bounce off the ship and come straight back towards its origin…

Post by NooneAtAll3 » Fri, Mar 20, 2026, 7:58 PM UTC

MengerSponge wrote: post #271

ajross wrote: post #243

Earlier quoted context omitted.

> it's actually very hard to find a ship, even as large as an aircraft carrier, in the ocean I just ran some googled numbers over my envelope, and I get that the Mediterranean sea (great circle distance between Gibraltar and Beirut is 2300mi) is about 14000x larger than the bow-to-stern length (858') of the carrier. That's... not that terribly difficult as an imaging problem. Just a very tractable number of well-reso…

And you've defined a harder problem! Once you've found it once it's much easier to find in the future: it can only go so fast, and it's constrained to stay in relatively deep water.

Post by kergonath » Fri, Mar 20, 2026, 7:59 PM UTC

garyfirestorm wrote: post #208

elif wrote: post #77

I seriously doubt there is a country on earth which lacks the capability to detect an aircraft carrier's presence in the Mediterranean sea. We are not talking about stealth vehicles.

We couldn’t find a commercial jet (MH370). Both, while it was still flying in the air and after it was presumably lost in the ocean. They couldn’t track it in the air nor can they still find its remains after looking for it for so long. This problem is not trivial.

Post by wolfi1 » Fri, Mar 20, 2026, 8:01 PM UTC

cbsks wrote: post #128

deepsun wrote: post #89

Earlier quoted context omitted.

Mediterranean maybe (although I'm not sure), but it's actually very hard to find a ship, even as large as an aircraft carrier, in the ocean. The empty space is just too big. Satellites have hard time taking pictures of every square mile of a sea to find any ship, yet alone the one you need.

I really don’t want to work for the defense industry, but I have to admit that they do have very fun problems to solve. You know there are people at NRO who are dedicated to ship tracking via satellite. I assume they can easily track ships without cloud cover, but how do they do it when it’s cloudy? Heat signatures? Synthetic Aperture Radar? Wake detection?

Post by tehjoker » Fri, Mar 20, 2026, 8:03 PM UTC

wahnfrieden wrote: post #279

drivebyhooting wrote: post #269

Earlier quoted context omitted.

I wish defense paid better. The problems are infinitely more interesting than ads. And it’s not like social media is a saint anyway.

Hmmm on the one hand murder, on the other hand ads