Satellites Spotting Ships
tech.marksblogg.com
tech.marksblogg.com
Just wondering since the distribution of locations shown in the blog post seems particular.
Be forewarned, there is also a ton of other data to wade through, but if you find and click all the right boxes the results can be pretty interesting (island wind wakes, ocean current visualizations, etc):
https://ovl.oceandatalab.com/?date=2024-02-13T12:00:00×...
For example: https://www.skylight.global/
https://spacenews.com/nro-signs-agreements-with-six-commerci...
- SAR
- Optical
- NRD
- LIDAR
- AIS / VMS / LRIT
etc.
Truth be told, detection tends to be a fusion of sensors. When it comes to non-cooperative objects, sensors like SAR, Optical, NRD, LIDAR are often used. NRD sensors detect ship navigation radar on S- and X-band, while LIDAR detects light from ships. Optical and SAR everyone knows.
It is my understanding that phased-array antennas, of the type Starlink satellites carry, are also excellent for phased-array radar.
It's known that Starshield covers both military use of the civilian Starlink network, as well as military-dedicated satellites for communications and other functions. I suspect that during wartime Starlink will be the world's most comprehensive (and, thanks to its scale, most survivable) space-based radar system.
They would be most useful for communications and possibly enable interference mapping.
Or finding Ku-band VSAT terminals of other users.
Background: I used to be an weapons engineering officer working on future radar systems back in my Navy days.
The total area a radar satellite (or an optical one) can scan at any particular time is very limited. A satellite, even multiple ones, will only see an airliner if it happens to be in the right spot at the right time.
Because nobody is looking. Umbra doesn't provide realtime global coverage, any location is only visited once per week. The chances of a specific location being captured right as a rogue airliner is flying over it are basically zero.
I also wouldn't be surprised if it didn't record any data over the open ocean. The vast majority of it is just waves, and nobody is ever going to pay for petabytes of empty images, so why bother? Same with capturing airlines at all: they are essentially always image artifacts, so I would expect them to be deliberately filtered out quite early in the pipeline.
I wouldn't be surprised if the US military had the capacity to track airplanes from space. But tracking every single commercial airliner, on the extremely remote chance that one of them goes rogue over a remote ocean? Not a chance, it'd be extremely expensive and provide zero strategic benefit.
https://veteranlife.com/military-history/diego-garcia/
"The base is home to thousands of American troops, sophisticated radar, space tracking, and a communications facility."
You know what’s huger? The Indian Ocean. Add to that the lack of blue-water competition in it and it’s totally reasonable that any birds we have in the area are craning their necks north, not down.
No amount of money can break the laws of physics and, like any sensor, radar has fundamental limits in range and resolution. MH370 flew into one of the most remote parts of the ocean it’s possible to reach, it would’ve been a miracle if it was tracked by any radar.
I've seen analysis that showed the flight was within range of several over-the-horizon radars at the time of disappearance and for hours after, ie - someone should know more than we do. As often with such things, I can't find it again.
Nor do OTH radars always operate at maximum efficiency: They achieve their longest ranges by bouncing signals off the ionosphere, which is severely affected by prevailing space weather.
The only radar that it likely did pass through was Australia's JORN, but the western sector was not operational that night and isn't on 24/7 because of cost constraints.
Yes, governments would love to have global 24/7 coverage even over the open ocean. In practice that’s neither possible nor practical.
Given their strategic advantage, you can bet the military will have prioritised steerable.
I disagree with the general premise regarding global coverage. With the US military, capabilities, especially in surveillance, have historically been shown to be decades ahead of what the public thinks is possible.
Personally, if a post appeared tomorrow showing some HN had figured out how to trace the movements of any airliner, without using its adsb and relying instead on anything and everything else that's publicly available, from satellite imagery, to radio frequency data, to radar, even weather data (contrails are often detectable), it would seem cool, sure - but, not unbelievable.
That hypothetically believable scenario would be one person, with no budget, in likely a few weeks or months of their spare time.
The US military has trillions of dollars, the best talent in the world, and decades of dedicated effort in exactly this area, and a propensity to keep such advances secret for decades (as shown recently enough by the Trump photo).
This is not something you can really prioritise. OTH radar designs are a trade-off between range, angular resolution, frequency, and mobility. For the longest-ranged systems with good angular resolution you can't steer them outside their set beam pattern, because their sheer size makes that kind of steering impossible. So if you want steerable radars you necessarily have to compromise on range, angular resolution, etc.
> I disagree with the general premise regarding global coverage. With the US military, capabilities, especially in surveillance, have historically been shown to be decades ahead of what the public thinks is possible.
Again, there are fundamental limits here. As much money as the US military has, it can't break the laws of physics. We also have a good sense of what types of assets it has and where they are, including satellites.
> Personally, if a post appeared tomorrow showing some HN had figured out how to trace the movements of any airliner, without using its adsb and relying instead on anything and everything else that's publicly available, from satellite imagery, to radio frequency data, to radar, even weather data (contrails are often detectable), it would seem cool, sure - but, not unbelievable.
Doing so over the vast open ocean would indeed be unbelievable. Even doing so for an individual over an ideal location would not be believable, as available resources don't make this possible at any real scale with the necessary granularity.
> The US military has trillions of dollars, the best talent in the world, and decades of dedicated effort in exactly this area, and a propensity to keep such advances secret for decades (as shown recently enough by the Trump photo).
See my point above. As for the Trump photo, by which I presume you're referring to the satellite image of the failed Iranian launch, the displayed resolution was within what experts had already presumed was within the capabilities of deployed US satellites given all available information. The photo didn't display surprising capabilities, it merely provided an official confirmation about what was already widely assumed.
1) Electricity usage
2) Staffing costs, both for operational control and ongoing maintenance and support
3) Parts replacement costs. The more you use the radar the faster its components wear out
I'm doing research on radars at a lab, but on automotive and robotics scales and operating costs are just not something we consider.
I can imagine so. For context, OTH sites are generally massive with hundreds of large antenna elements. This article has some pictures of one of the JORN sites as an example: https://www.australiandefence.com.au/defence/cyber-space/jor...
Also, the over the horizon radars are in Australia. I think they could have picked up the flight but were offline that day.
Yes, that’s the JORN system. The western sector might’ve picked it up if it went near western Australia as presumed, but it wasn’t operating.
Also, tracking has gotten much better. There are ADS-B receivers on satellites that can cover the whole globe. But nothing helps if plane turns off its transceivers.
As others have commented, there is also a difference between ultra-high definition pictures of precise locations and sweeping entire oceans.
I just wonder how many SAR sats we don't know about.
Most SAR systems operate in X-Band (~10 Ghz). I guess it's fair to assume that every organization who has ever sent anything to space has also launched SAR satellites. The radar part is comparatively easy to getting things into orbit.
Your point is taken though, tons of remote sensing signal you can fuse to detect malicious marine activity (I'd argue in real time). If you can detect the ship from orbit, and the AIS doesn't align with owner, cargo, and previously expected route (or there is no AIS), strange things are afoot.
Maybe there is a variable I’m missing?
Now your average Joe can track them from their desktop for free.
So you have to have a pretty good idea where the carrier is, and then you get an image delivered with some latency as the satellite will need to pass over a ground station that downlinks the data.
So it isn't free (although umbra has a CC BY 4.0 license for their data, much more permissive than other providers. Nor is it easy to search huge amounts of the ocean for the carrier.
What most entities probably do is tip and cue, which is use a sensor with coarser resolution to get an approximate location and then use a sensor with finer resolution to look closer.
And they will also have their own satellites.
Even then, aircraft carriers being unsinkable was a myth.
“In 1942 the US lost as many carriers as the Japanese—and a larger percentage of their overall carrier force” to the extent that it “was almost out of carriers in the Pacific in late 1942.”
“Why the US ended up winning the war in the Pacific was therefore not because of the fleet that they started the war with—it was the fleet that they ended it with—almost all of whose most effective and advanced warships were launched after the Battle of Pearl Harbor on December 7, 1941” [1].
[1] https://phillipspobrien.substack.com/p/war-and-deterrence-in...
> “Why the US ended up winning the war in the Pacific was therefore not because of the fleet that they started the war with—it was the fleet that they ended it with—almost all of whose most effective and advanced warships were launched after the Battle of Pearl Harbor on December 7, 1941”.
Considering that the tonnage of ships the US had was limited by treaty (treaties were expired, but it takes time to build ships) and that Japan's attack further reduced the fleet strength, one would expect that the US won with ships built after Pearl Harbor.
There was an 18 month period in which the US built more fleet carriers than Japan had in the entire war. In addition, Japan lost a huge fraction of their experienced pilots in 1942, which was arguably as deleterious as losing the carriers.
Which is to say that the Black Sea / Red Sea is not the Midway Atoll with its wide-open ocean.
I doubt that; Russian land-based air defense is struggling in a similar fashion. Very little get anywhere near Ukraine's Patriots, while hand-me-down NATO-supplied weapons are happily taking out S-300 and S-400s in Crimea. As for drones, the US has been dealing with small-boat attackers for significantly longer; I'm sure they're using lessons learned in Ukraine to improve, but in jet ski versus CIWS in open waters, I'm betting on CIWS.
(That said, you would indeed avoid getting a carrier group stuck somewhere like the Black Sea.)
> hence why USS Eisenhower had to escape 200 miles North to Jeddah once it started being targeted a few weeks ago
Notably, it's not on the bottom like the Moskva.
Being able to pretty effectively take down threats doesn't mean you need to unnecessarily risk it, but Russia's difficulty a) defending against NATO missiles and b) striking back against NATO air defense in Ukraine should give folks like China some serious pause in their own planning.
Not sure about that, plane-launched FABs are creating havoc on the Ukrainian front-lines.
> Being able to pretty effectively take down threats doesn't mean you need to unnecessarily risk it
Of course, but that's how you get to the "Fleet in being" [1] situation, which I'm not sure it's the ideal solution for the US Navy, which (afaik) consumes about a third of the US military budget. I mean, how would the US Navy commanders be able to explain that they're spending that much money only for their magnificent warships to avoid direct battle contact?
> striking back against NATO air defense in Ukraine should give folks like China some serious pause in their own planning.
Neither China nor Russia depend on their fleets in order to win existential wars for them, as they're both continental powers, so not sure a Russian cruiser ending on the bottom of the Black Sea will make any strategic difference. Also, geographically speaking there's no sea between South Korea and both Russia and China, and the sea distance between the same China and Taiwan is pretty small, they'd be able to provide artillery/missile cover for it entirely from land.
The Patriots aren’t on the front lines, and weren’t allowed to even shoot at the planes lobbing bombs from Russian airspace until just recently.
Attempts to knock them out have failed. The same is not true for the Russian equivalents deep in Crimea.
The idea of the US Navy as a “fleet in being” is simply absurd at the present time.
That is false, which is why Romania, my country, has just approved sending one of its (only) two Patriot systems to Ukraine.
> The idea of the US Navy as a “fleet in being” is simply absurd at the present time.
It is absurd if you ignore the facts on the ground (on the sea?), and the facts show that the USS Eisenhower has chosen to avoid direct confrontation with land-based missiles shot by the Houthis.
More generally, people should try to look closer at the facts as they are happening (again, saying that Ukrainian Patriot systems have been unaffected this far into this war is just ignoring facts), that's good advice for any war, past, present or future.
Chinese are hopelessly dependant on imports of raw commodities (most notably oil), a naval blockade would sent them back into Middle Ages in a matter of a couple of years. Hence, their continous existence is contingent on strong navy. Which they presumably get, seeing how much they invest in it.
Good thing for them that Russia is just next door.
Currently they have about a 100km range.
The subs can fire from far away, move and fire again from different angles.
A ship could have dozens coming from all directions.