Successfully Testing Satellite-Based ADS-B Tracking | Hacker News Reader

Successfully Testing Satellite-Based ADS-B Tracking

blog.flightradar24.com

66 pointsSami_Lehtinen18 comments

That looks awesome! Hopefully in the future they will indeed achieve global coverage, or at least cover the oceans to make it easier to find lost planes.

All we need to do next is not allow airplanes transponders to be turned off

...or circuit breakers to be pulled, or any humans in the loop at all...

And design transponders so they never go wrong and need to be turned off, and electrical supplies that never need to be turned off, and electrical generators and transfer switches that never go wrong such that shedding the load of the transponder is useful in an emergency, and redesign the parts of the radar system that assume that pilots turn off their transponders when nearby.

In 2001, Russia shot down civil plane approaching it border because of it transporder was turned off (then blamed Ukraine).

https://en.wikipedia.org/wiki/Siberia_Airlines_Flight_1812

Did you link the correct flight? Because your link says something entirely different.

Yep, it says entirely different because Russians are exceptionally good liars. But if you read court documents, then you will see that no hexogen is found at plane crash site, which is impossible for missile warhead made with 60% of hexogen. Moreover, military training was recorded on video, and this record was shown right after incident. 3 missiles was launched, 2 of them hit their targets, one missed. Third rocket blown up in the air by command from ground. Moment of blow up is visible on video.

I had small battle in Wikipedia and won. Now page says correct information.

Well, "or at least cover the oceans to make it easier to find lost planes.", some airlines (especially Lufthansa) do have that already.

They also provide in-flight internet even on flights over oceans via satellite.

Most airlines just don't have it cause they are too cheap.

That's easy enough for Lufthansa considering their routes. But there are still areas with no satellite Internet coverage available at any price.

The price of launching a set of satellites that covers that area divided by the number of customers that will use it over the number of years that's in service? That's a price.

The GOMX-3 (https://directory.eoportal.org/web/eoportal/satellite-missio...) is a pretty cost effective satellite. I bet you could put a dozen up as 'ridealongs' with one of the ISS resupply missions.

One issue is getting the different orbital planes covered. Its possible with an "upper stage" booster[0], but that is significantly more expensive than a typical CubeSat carrier/deployer[1] for the ride-along launches. As far as I know, there is no current smallsat/cubesat sized upper stage intended for changing orbital planes.

[0] https://en.wikipedia.org/wiki/Centaur_(rocket_stage)

[1] https://en.wikipedia.org/wiki/NanoRacks_CubeSat_Deployer

Iridium has complete global coverage.

They're also certainly not providing internet to passengers via Iridium, because Iridium data is extremely, hilariously expensive. Sending back basic airplane telemetry via data satellite is quite practical though because it's a very small data volume, and is already often done by engine leasers (like Rolls Royce and GE) for continuous engine performance monitoring. It's rather depressing that on many aircraft in the air today, the engines are better monitored than the actual plane.

There are different motivations though. It pays for GE and RR to collect constant engine telemetry so that they can micro-optimize service intervals (read: perform service as infrequently as possible). The airlines, though, have physical possession of the planes and tend to figure they'll work that kind of thing out on the ground when planes are out of service for several hours anyway.

Would it be wise to install different radio equipment on planes? Would it make more sense to use an up-ward facing directional antenna? Also, is ADS-B 1090Mhz really the most reliable way to send signals to a satellite?

>> up-ward facing directional antenna?

That would only add more limitations. The sat isn't always directly overhead. Directional limitations open up the possibility of random signal loss, such as when a plane is turning away from the sat. This would appear as a dropped signal until the sat came around again, perhaps an hour or more later. If this is to be used as a black box then handshakes need to be as reliable and regular as possible.

Omnidirectional units (on the aircraft) are also cheaper and allow improvements to be made on the sat side of the equation without new hardware on the more expensive aircraft side.

Signal strength doesn't seem to be an issue anyway. A SPOT unit can transmit every five minutes for days on a set of AAA batteries, and that's going all the way out to geosync.

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