this post was submitted on 20 Mar 2026
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[–] kahjtheundedicated@lemmy.world 94 points 2 weeks ago (21 children)

As funny as that is, something tells me it’s not that hard to spot an aircraft carrier in the Mediterranean

[–] DaddleDew@lemmy.world 69 points 2 weeks ago* (last edited 2 weeks ago) (19 children)

You have to be in visual range, or radar range if you have one, which is the horizon plus a bit more depending how high above sea level your are and how tall your target is.

If you're on a ship, unless you're using an advanced radar that bounces signals against the ionosphere or you have a meteorological phenomena called an inversion which can curve your radar energy over the horizon a little bit, your radar horizon is surprisingly short, something around 12 nautical miles give or take. And the sea is big and Iran is quite far.

This is one big reason why aircraft are used for surveillance at sea. They can go much higher than any ship's radar antenna mast every could be which significantly expands their radar horizon. They can also scan a huge area relatively quickly as they can travel much faster.

Because if this fuck up, Iran now has the intel that the French carrier is approaching without even having to send an aircraft out to look for it. If they even still have the ability to do so at this point.

[–] Randomgal@lemmy.ca 34 points 2 weeks ago (4 children)

So satellites can see my truck's plate but an aircraft carrier and it's escrow fleet are too... Small?

[–] astronaut_sloth@mander.xyz 36 points 2 weeks ago (1 children)

Sort of. Satellite resources are surprisingly scarce, so a lot are focused where people are, i.e. land. Plus, for the imagery sats that are focused on the ocean, ships are also tiny in a literal ocean of blue. It's just a spec. While the resolution could be good, have fun looking for that spec. That's why most countries use signal collection to locate vessels at sea. (I'm over-simplifying a lot, but you get the picture)

[–] FauxLiving@lemmy.world 14 points 2 weeks ago* (last edited 2 weeks ago) (1 children)

While the resolution could be good, have fun looking for that spec.

Seems like an simple but tedious job. Something that a computer can do.

Object detection algorithms are incredibly fast and can learn to tell the difference between an aircraft carrier and an ocean.

[–] astronaut_sloth@mander.xyz 12 points 2 weeks ago (1 children)

There are a surprising amount of false positives when using object detection on maritime imagery. While a carrier is a spec, there are a ton of specs in the ocean that can look similar enough. Plus, weather has a huge hand to play. If it were always perfectly clear, then it's an easier problem, but one cloud can really mess up the detection. Ultimately, ship detection is a difficult problem (not intractable but still hard).

[–] FauxLiving@lemmy.world 3 points 2 weeks ago (1 children)

False positives are fine, you assign 1, 10, 50, 100 analysts to review hits. You only need to find it once, then the search area becomes incredibly small for each subsequent satellite pass.

I'm not saying that it is easy, just that you don't need to have a surface ship within 15 nm in order to see it.

[–] EddoWagt@feddit.nl 1 points 2 weeks ago (1 children)

I'm not saying that it is easy

It kind of sounds like you're saying that. Anyways, there's a reason submarines exist

[–] FauxLiving@lemmy.world 1 points 2 weeks ago (1 children)

It is simple, it is not easy.

'Take a picture of the entire ocean and look for ships' is simple, but executing that plan is not.

It requires hundreds of millions of dollars of reconnaissance satellites, and an entire branch of personnel to operate and digest the information.

This is why the US operates carrier battle groups instead of just sailing their carriers everywhere with a small escort. They can't hide, but they can pack enough offensive and defensive power into a tiny area to make most attacks infeasible.

Anyways, there’s a reason submarines exist

True, and even they're vulnerable when they surface (if they're moving), the v-shaped wake is also very detectable from space where satellites can detect wave heights within 3cm. It's not easy for humans to find, but with billions of dollars to spend on computers, these kinds of things are very much within the reach of sovereign nations.

[–] thebestaquaman@lemmy.world 1 points 2 weeks ago

I agree with the premise of "simple but hard". However, I still want to underscore that large areas of the ocean will at any given time be covered in clouds or fog. Sure, once you find the ship the first time, you've narrowed your search radius significantly, but a ship that can move at 30 knots can move around 1500 nautical miles (2800 km) without being seen under just 48 hours of cloud cover. That means any intel on the position of a ship carrying weapons that can easily strike at ranges of 500-1000 km is fresh produce. Just a day after you spotted that ship, it can have moved almost 1500 km, and if you lose track of it under clouds during your next satellite pass, it can suddenly be 3000 km from where you last spotted it.

What this means is that the "hard" element here is significant. Even the "simple" element becomes complicated by stuff like night time and cloud cover. All this taken into account, there are very few countries in the world with enough surveillance satellites and processing capacity to actually keep a pin on a ship at sea over any significant period of time.

[–] UnspecificGravity@piefed.social 4 points 2 weeks ago

It depends a great deal on if you have access to a real-time satellite feed and know where to look.

[–] Iconoclast@feddit.uk 1 points 2 weeks ago

You still need to know where to point that spy satellite's camera at. If you take picture that covers hundreds of square kilometers then you don't have enough resolution to spot the ship but you can't zoom in much either because you don't know where to zoom.

It's different with buildings because you know where they are.

[–] theneverfox@pawb.social 0 points 2 weeks ago

It's the ocean. The majority of Earths surface where there's usually not much going on

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