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At the risk of being marked as a duplicate question, i am raising my first ever question in aviation.

I have always wondered how/why of aircrafts positioning, ever since the "lost" plane of Malaysian airline. Here are few things that are still unclear to me -

  1. We have fairly precise GPS service available to cars/phones etc. why cant the same be availale to planes? And more importantly, why cant the planes reciprocate with their own coordinates ? Better if it can be shared in real time ? What are the challenges?

I have read some about ADS-B a little and understand that it has its limitations. owever, when we have so many human lives at stake, why is a better solution looked into/implemented?

The limitations that have been described for ADS-B systmes is pretty serious, given that many of the aircraft today travel through horizon boundaries.

  1. How exactly do "people" get to know of a aircraft and/or its position in order to "potentially" strike it using a missile etc? Is any of ADS-B data available publicly allowing a plane to be tracked by "anyone"? if so, why also, isnt that encrypted, and if not, why not?

My thought process is mostly around "how can someone track a plane without being part of the ATS system/network"?

  1. What are the areas of our planet not covered by navigational satellites ? There are references to lack of navigational satellite coverage in many areas on earth. For that reason, I want to understand more on that topic. For an aeroplane, flying on a given route, transmitting its position to a satellite above, what are the potential challenges?
Ralph J
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Raghav
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    Why do you think ADS-B needs to be secret/encrypted? What incidents have occurred that could have been prevented? The only recent incident of a downed airliner almost certainly occurred because the groups in question thought it was military - something that could have been ironically avoided by the use of some kind of flight tracking. – Dan Nov 02 '15 at 11:38
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    This is really three questions, of which the first is a duplicate, the second doesn't make a huge amount of sense, and the last is unclear. If you have multiple questions, please could you put them into separate threads with one clear, non-duplicate question in each? – Jon Story Nov 02 '15 at 11:50
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    Possible duplicate of Why don't all commercial aircraft transmit GPS data in real time? – Simon Nov 02 '15 at 11:57
  • The duplicate question answers almost all this. The main point most people don't understand is that GPS only receives. It does not transmit the position. An aircraft knows where it is just as well as your car, but no-one can track your car from GPS. – Simon Nov 02 '15 at 11:59
  • @Simon - As i know, the data is provided anonymously, and therefore i am not trackable, however as a collaborative system, everyone benefits from transmitting their position to the central system core. I understand that while using my car's GPS, i am receiving as well as providing data to the navigational systems. which is how they can track and tell me where the jam is forming as it happens. – Raghav Nov 02 '15 at 12:11
  • @Dan - Well, if the information is publicly available, it can certainly be misused. Almost all mishaps have a certain element of "third party involvement", unless confirmed otherwise. If the ADS-B informaiton is encrypted, that perspective would be highly discounted. – Raghav Nov 02 '15 at 12:13
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    @Raghav You're GROSSLY misunderstanding how GPS and Satellite Navigation work. GPS is one way only - no ifs and buts, all you get from GPS is a Latitude / Longitude location and an estimate of accuracy depending on the amount of satellites involved. Everything else relies on 3rd party propriety systems - that's everything from the map you see to route planning, traffic data and so on. For your domestic sat nav, that either relies on radio transmissions to tell you about traffic (Again,one way only) or internet based communications. – Dan Nov 02 '15 at 12:17
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    @Raghav But misused how? You're making claims and assumptions that aren't really based in reality - to take down an aircraft in cruise you either need to be on board it, or have access to very serious anti aircraft weaponry. Neither of which are going to be heavily dependent on something like ADS-B. – Dan Nov 02 '15 at 12:19
  • @Dan - you are absolutely right, without those kind of weaponry, nothing is possible. I am only looking at the tracking perspective, not on the other areas. Also, I am not trying to make any claims at all. Just thinking about "potential" problems that can come about if such information is in wrong hands. – Raghav Nov 02 '15 at 12:20
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    the data is provided anonymously. No data is provided. GPS satellites do not receive data. They only transmit data. The GPS in your car, or on an aircraft, can only receive data. They might send data to another system, but that is not GPS. You should carefully read the duplicate and linked questions and answers and also read some basic articles on how GPS works. You cannot track anything with GPS. – Simon Nov 02 '15 at 12:32
  • Just want to add that there are no areas of earth not covered by navigational satellites. – TomMcW Nov 02 '15 at 17:34
  • Raghav, The planes all over the world can transmit to communication satellites (not GPS satellites) their GPS coordinates but the data traffic made by the planes will be too high. There will be more than 10 000 satellite calls at least twice a minute (an aircraft travels 15 km/min, there could be 10 000 planes in the air at each moment). Such a large number of calls loads too much the existent satellite communication networks. – Robert Werner Nov 02 '15 at 17:48

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