40 years ago the USN was working on using SAR with a elliptical kalmann filter to detect _submarine_ wakes. I assume things haven't digressed since then.

BigTech ought to renamed too. BigVice maybe?

Would you prefer to lose it first?

To get a naval fix, you usually define an "area of uncertainty" around the last confirmed location of the ship. The area is usually a circle with the radius being the maximum distance the ship/group could travel at full speed.

So, you don't exactly "know" where the ship is, but you can draw a hypothetical geofence around where it's likely to be, and scan that area.

Figure out where you can't buy pictures to narrow it down, if you want a more exact match, pay for pictures from that area from non US providers.

Planet Labs PBC, a leading provider of high resolution images taken from space, said Friday it would hold back for 96 hours images of Gulf states targeted by Iranian drone attacks.

It did not say if it had acted at the request of US authorities.

https://uk.finance.yahoo.com/news/leading-satellite-firm-hol...

Do them publish the banned coordinates in a list too? Maybe they could put the reason at each line.

You certainly can't do continuous observation but even just with commercial satellite offerings you can get pretty close.

For example nowadays Planet Labs [1] offers 30-50cm resolution imaging at a rate of one image or 120sec video stream every 90 minutes over a given 500 km^2 region. There is no situation where an aircraft carrier is going to be capable of evading a commercial satellite offering with that frequency and resolution. Once you know approximately where it is or even where it was in the semi-recent past, it's fairly trivial to narrow in and build a track off the location and course.

1. https://www.planet.com/products/satellite-monitoring/

Commercial operations like Planet Labs currently cover most of the Earth multiple times a day.

SAR is not blocked by clouds.

Break out the pocket book and pay Planet Labs to do it. You could do it with much less frequent visits than this probably the search area for it every 2 hours isn't very large and image recognition systems are pretty good. The big threat is cloud cover.

https://www.planet.com/pulse/12x-rapid-revisit-announcement/

...literally yes (to the latter)? Is that not exactly why modern warships have to implement things like measures to reduce their radar cross section? If you could actually just rely on "ocean too big" then there would be no need for that.

You don't even need a free account on flightradar24 to track its planes, at least two launch from it and pattern circle around it almost daily.

Even with an extremely low resolution radar hit they are very identifiable.

Most naval vessels move in groups/squadrons. Carriers basically always travel with a "carrier strike group"/CSG of a dozen other ships and destroyers often travel in "destroyer squadrons"/DESRONs. So any time you see a cluster of hits, just by the relative responses of each hit you can narrow down and guess the entire CSG/DESRON in one go and then work out which responses map to which ship in the CSG/DESRON once you have a good idea of which group you are looking at.

This is especially true because ships even within the same class have varying ages, different block numbers, and differing retrofits. So each one has a unique signature to it.

But also if you aren't completely certain you can always come back with a second high resolution pass and then it's trivial to identify each ship just visually.

> I would think

Just do a youtube search and you'll find plenty of talking head explainer videos. Ignore the talking head and just look at the imagery and data they share.

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 original source. You get tons of energy coming back at you.

A ship on the ocean is basically a dihedral corner reflector, which is a very good target for a radar.

> 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 you locate it with the wide sensor swath and then get a detailed radar signature from a more precise sensor?

That's one approach, there are so-called "tip and cue" concepts that do exactly this: a lead satellite will operate in a wide swath mode to detect targets, and then feed them back to a chase satellite which is operating in a high resolution spotlight mode to collect detailed radar images of the target for classification and identification.

However, aircraft carriers are big, so I don't think you'd even need to do the followup spotlight mode for identification. As an example, RADARSAT-2 does 35 meter resolution at a 450 km swath for its ship detection mode. That's plenty to be able to detect and identify an aircraft carrier, and that's a 20 year old civilian mission with public documentation, not a cutting edge military surveillance system. There are concepts for multi-aperture systems that can hit resolutions of less than ten meters at 500 km swath width using digital beamforming, like Germany's HRWS concept.

tl;dr: Radar works very well for this.

I am always open to corrections from specialists in the field or just any average joes with a different opinion. That's why I keep coming here.

They don't normally go that fast from what I understand. That is their top speed in reserve they can use for evasive maneuvers, they don't want to go faster than their support fleet or deal with the high maintenance running at threshold will cause.

It's like when you drive your car you're not normally redlining it since that will kill the engine if you do it all the time.

They don't but it shows they could.

Who is Iran a proxy for? Russia, as usual, has only benefited from Trump's actions.

The one thing you can say about Iran is that they were absolute morons not to actually build or otherwise acquire a nuclear arsenal. They had decades. If Pakistan could do it...