Flightradar24 ADS-B Receivers On-board a Surface Ocean Robot | Hacker News Reader

Flightradar24 ADS-B Receivers On-board a Surface Ocean Robot

blog.flightradar24.com

138 pointsdewey61 comments

For anyone interested in how this robot is getting around the ocean...

>> Wave energy is greatest at the water’s surface, decreasing rapidly with increasing depth. The Wave Glider’s unique two-part architecture exploits this difference in energy to provide forward propulsion.

http://www.liquid-robotics.com/platform/how-it-works/

while i love the platform, fr24 filters results so you arent likely to see ultra-cool stuff. adsbexchange does a more open job of not filtering submitted data.

Can you give an example of this ultra-cool stuff? :)

Military aircraft?

if you give a man a URL he will surf for a day, if you tell him to go to adsbexchange and set up his own filter to see ultra-cool stuff, he upvotes the source.

High profile aircraft (ie Trump Force One) tend to ask for their data to be scrubbed from these sites and the sites typically comply; however the data from those planes is still transmitted unencrypted over open airways for anyone to listen in. A network of people who share data could reconstructed and view the data that others wanted removed from public view.

A network of these, with logging of historical data, would very possibly have helped with MH370 / Air France 447 etc. If they can maintain coverage of most of the oceans, this'll be an incredibly useful tool for future lost flights... not to mention real-time updates for flight arrival times etc. I'm amazed that we currently don't have any idea where aircraft are (except self-reporting) over most international waters...

Not likely as I believe they turned off the transponder, which is what these devices listen for.

That's correct, in the case of MH370.

ADS-B is essentially self-reporting.

Maybe the disappearance of the transponder signal could trigger another method of investigation, e.g. visual tracking via Planet Labs network of satellites.

Planes have a variety of transponder options available, all of which can be turned on/off independently. Mode C (and sometimes Mode S) is the most common today and most important for entering controlled airspace (most airspace in the US is controlled). While ADS-B is an option, it's not yet mandatory (making its practical uses less than ideal in many cases). It won't be mandated until Jan 1 2020 in the US, and the first FAA laws on the ADS-B transponders were not published until May 2010.

Source: https://www.faa.gov/nextgen/programs/adsb/faq/#g1

ADS-B is amazing, yet I also find it's amazing it took so long to become more popular given how helpful it is. With an ADS-B receiver (I always have a stratus 2S on board while i fly) you get info like the call signs, speeds, positions and altitudes of other aircraft, while a Mode C transponder simply is a pinging beacon that air traffic can use to identify primary (radar based) targets. Mode C/S will give the pilot no advantage other than knowing that ATC can see them.

Sadly in my case I only have an ADS-B receiver and no transmitter combined with a Mode C transponder, so i get some situational awareness and weather updates, but I do not contribute to the 'vision' of other pilots with my device.

Stratus 2S: http://www.sportys.com/pilotshop/ipad-iphone-android/ipad-gp...

Amazing.

Maybe I'm extremely naive, but it seems to me that you shouldn't be able to turn the transponder off in a commercial passenger flight, and that international medium/long-haul flights that are likely to be in areas with reduced transponder coverage should be required to have some sort of Iridium beacon (which also cannot be turned off).

Even sending the coordinates every 15 minutes would greatly reduce the area to search, and preventing disabling the transponder safeguards against nefarious or suicidal crew/passengers/terrorists.

If I didn't know better (MH370), as a laymen I would have assumed all major flights would be sending their GPS locations constantly via satellite already, for a slew of reasons (one of them being it's 2016).

There's always a fuse you can pull. And there needs to be a fuse, per regulations on how to build aircraft.

The stray MH370 signal was coming from the engines directly, presumably powered by the engine's internal power system, and it was engine performance telemetry to be sent to the engine manufacturer. The pilot might not have known about that system or unable to disable it (without shutting down the engines).

This is the key point, in the case that there is a fire on board (one of the likely possibilities with MH370) you want to be able to disable the offending circuit immediately. If that happened to be your transponder, so be it...the transponder really adds no value to the plane in terms of its ability to stay in the air, so disabling it and extinguishing the fire is the key priority over giving ATC the ability to identify you on radar via the transponder.

But there can be a luggage fire? What fuse can you pull to disable that? I assume there are extinguishers for the luggage compartment?

Put a GPS/Iridium suitcase in the plane?

There are extinguishers in the cargo area. I'm not sure who manufactures it for the 777. The general setup is fire, smoke, and overheat detection systems throughout the aircraft. This information is relayed to the pilots. Some of the extinguishing mechanisms may be automatic (more common in military and not so common in commercial). Cargo areas probably use halon or similar.

The point is that you should be able to disable anything that is connected to the planes electrical system, to stop fires and prevent damaged systems causing issues with other functional systems (i.e. broken GPS causing electrical surges should be disabled to ensure other controls continue to work).

Unless your luggage is plugged in, this is something that ground based security should be assessing the risk of prior to placing it in the plane, followed by the redundant fire suppression systems in the luggage hold as a last resort, this should be fairly under control by the time the plane is in the air.

> ADS-B is amazing, yet I also find it's amazing it took so long to become more popular given how helpful it is.

How much of this is the FAA dragging it's feet on NextGen projects? It's astounding that after billions being poured into "security" they still don't know exactly where every aircraft it at all times.

Who are Flightrarad24 clients? Why do they care about planes in the middle of nowhere :) ?

A lot of enthusiasts are a big part of that I guess. I've been a paying user for quite some time now and I primarily use it as a few minutes of distraction every day.

see https://news.ycombinator.com/item?id=12441989

> The problem is that there are large blind spots when aircraft go over oceans due to the lack of receivers, so this is intended to increase coverage.

My company pays to license their feeds for our own use. I think that their business model is fairly solid.

what does your company do?

If I had to guess, something with finance. Observing meatspace logistics allows one to draw certain conclusions earlier than the rest of the market.

Right now, there are people observing chinese factories, reporting number of shifts etc. to some guy in a remote office.

haha, the stock market is such a funny game. thanks

That's a big one but FR24 isn't as useful for that nowadays as they mask private aircraft on request of the owners. Private tracking networks are more relevant now.[0]

Conversely, many aviation enthusiasts are more interested in hyperlocal tracking where FR24 again loses-out to tightly-focused private networks.

So it's really aiming to position itself as a (1) business solution for fleet management and (2) for general travellers who aren't concerned with watching 'special' traffic but want to see where is their delayed United flight.

[0] However many of the same operators who have their aircraft publically hidden or masked also use FR24 for managing their own fleets as it's much cheaper than subscribing to datalinking through SITA or whatever.

They do it with satellites too, e.g. https://en.m.wikipedia.org/wiki/Terra_Bella

Indeed what a way to spend your short life, chasing currency by watching parking lots empty and fill while clicking buttons to move sums of digital funds around.

Supposedly one early use of radio telegraphs were to mount them on speedboats and race out to meet freighters. This to give the stock traders a early insight into the cargo coming.

As opposed to making the world a better place by optimizing remote databases to speed the distribution of semi-nude selfie photographs or something?

Don't know how to break it to you, but I am pretty sure we're all just on a very brief stint scurrying around pointlessly on a rock near an unregarded yellow sun located at the unfashionable end of the western spiral arm of the Galaxy.

>As opposed to making the world a better place by optimizing remote databases to speed the distribution of semi-nude selfie photographs or something?

Yes, that's not the same thing if you believe that people should generally work towards improving social utility[1]. It takes some significant mental gymnastics to convince yourself that getting a market edge over other funds to improve your hedge fund's performance at the expense of theirs is improving social utility. It's just concentrating wealth from some rich people (one fund's shareholders) to other rich people (your fund's shareholders). Maybe if you're lucky you'll even be taking money from retirement accounts.

Even if you argue that someone else would take the money if you didn't, that's not enough to offset the loss of so many people doing something so wasteful from an intelligence perspective. The current incentives draw significant portions of intelligent people away from doing something constructive for society (science, medicine, engineering, math) to competing in an information game for rich people.

1. https://www.quora.com/What-is-social-utility

It doesn't take mental gymnastics at all. One could easily make the argument that market intelligence improves the allocation of capital and makes the world more productive. One could also argue that creating web apps for wealthy westerners is even less useful to society. One could note that being a subsistence farmer doesn't really contribute to anything or leave much of a mark for the future at all, and be ok with that too. All of these are just ways of surviving, and none of them seem particularly indefensible morally. You gotta do something to get by.

As for your link to Quora, that's a completely incomprehensible rant, just FYI.

Ok, try to make that argument. How is pouring the limited resources of very intelligent people into deriving information correlated with unreleased sales figures making the market that much more efficient to offset that cost? It's effectively the same thing as having them wiretap company executives, just much less efficient.

Just FYI, it was an explanation of the term 'social utility'.

One of these potential users of this data:

* Air safety authorities * Aircraft companies * Travel data companies * Insurance companies

some of Flightradar24 and FlightAware clients include: Airlines, other aircraft operations, Freight services using aircraft. Airport Flight status display boards, Airport services, Tax officials etc.

I thought this was interesting "The GOMX-3 satellite orbits the earth approximately every 90 minutes at a speed of 27440 kilometers per hour" - https://blog.flightradar24.com/blog/tracking-flights-with-sa...

I was assuming it would be a geostationary satellite they would be using.

Does that mean they can only get ADS-B data from the tracker every 90 minutes?

I would assume so yeah. I'd be interested to know if there's any reasonably affordable satellite system that you could use for closer to real-time data.

My company, Spire, is doing fundamentally the same type of tracking as is described here, except for ships using AIS. By building a constellation of satellites with different orbits, and using a network of groundstations, you can achieve near-real time data. These would be no exception, it's just a matter of scaling up from one to n satellites and having the coverage of a groundstation network to support them.

Oh I read about your company in the Economist recently, I thought that was really cool! Here's the article, for anyone interested: http://www.economist.com/technology-quarterly/2016-25-08/spa... (the bit on Spire is in section 3). That you're also doing atmospheric measurements for weather forecasting seems pretty neat.

The Iridium NEXT satellites to be launched by SpaceX soon (well, we'll see about that ...) are equipped with ADS-B receivers, see e.g. http://aireon.com/resources/iridium-next/

No, the boat doesn't talk to the satellite. They're two different methods they're using to improve coverage.

Geostationary orbit is a lot further away. Presumably that's an issue for acquiring ADS-B signals.

Sorry I'm not sure what you mean, as I understand it, the ADS-B signals are just being acquired with a receiver on the 'boat' and then relayed via satellite.

They have two different things. One is the boat that is relaying the signals via satellite. Another one is a satellite that is directly capturing the signals (if I understood the link below correctly).

https://blog.flightradar24.com/blog/tracking-flights-with-sa...

Oh gotcha sorry, I misunderstood that link

My understanding was that those were two distinct methods they were evaluating not one combined method.

You can use any of the LEO/MEO Satcomm services that support simplex and/or duplex data transmission, which currently are Globalstar or Iridium. These are far easier to target since you don't need as much transmitter power resp. precise pointing like you need when talking to GSO satellites. Though, bandwidth is a trade-off, but I suppose the amount of data acquired by ADS-B receivers is less than the available bandwidth, especially in (relatively) low-traffic regions like the oceans.

Edit: To be clear, that only covers the data transmission part from the vessel and not picking up ADS-B signals. For the latter, the Iridium NEXT satellites will be equipped with ADS-B receivers directly.

> we have received and processed ADS-B signals collected by our autonomous boat...

I wish the article would've explained: (1) What is ADS-B, and (2) why does it matter. Without that context, I have no idea if this is significant or not...

EDIT: Given FlightRadar's business... I'm guessing it helps with flight tracking. This wasn't entirely apparent from an outsider reading that blog for the first time.

Aircraft broadcast ADS-B signals which contain tracking information, which is used by live flight trackers to map out each flight in real-time. The problem is that there are large blind spots when aircraft go over oceans due to the lack of receivers, so this is intended to increase coverage.

ADS-B signals (from my limited knowledge) are transmitted by aircraft showing some basic data like location, altitude, speed, callsign, aircraft model and a few other things. They only have a range of a few hundred kilometers so a website that does flight tracking using a global network of (volunteer) receivers, it's a step in their coverage to be picking up signals over the oceans.

Also it's just cool.

Good info on ADS-B https://www.renderlab.net/projects/ADS-B/

Also just google "Defcon ads-b", there are a few.

You can track planes over you with free software and a small homemade antenna:

Free software: https://github.com/antirez/dump1090

Inexpensive antenna: http://antirez.com/news/46

It's an industry specific, aviation, app. Chances are, if you are there you have a glancing familiarity with what it means and how it works. If you didn't know and were interested 2 minutes on Wikipedia would have you sorted out.

Unless writers are getting paid per word most computer blogs aren't defining CPU, GPU, USB, HDMI for their readers.

Why ADS-B instead of a transponder system for ships? e.g. AIS? https://en.wikipedia.org/wiki/Automatic_identification_syste...

Hmm, maybe ADS-B systems are more compact...

Given that the antennae are at surface level and the aircraft are probably between 25,000ft and 40,000ft, I wonder what the ideal maximum range of the receivers would be?

With VHF a handy formula is miles = 1.25sqrt(feet)

So 25000ft gives a range of ~190 miles, 40000ft gives ~240 miles.

Thanks! The target area is approximately 250 miles equidistant from Iceland & Norway, so it's feasible that one of these boats could cover the entire area (under ideal conditions).

ADS-B is not on a VHF frequency.

It is indeed UHF.

I should've put "VHF/UHF" in the original comment as the formula is reasonable for both. They're both Line of Sight and that's really what the approximation is about.

With a basic RTLSDR and a random small TV antenna (nothing optimized for this use case), from my apartment I've picked up airplanes that were at 40000ft and at a distance of ~ 100 km (62 miles).

Optimizing the antenna and the hardware (and using a lot less cable for the antenna than I have) would probably increase that significantly.

Won't barnacles be a problem?

Reply on news.ycombinator.com