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The Dark Side of ADS-B


FlyingMonkey

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For whatever reason, I was thinking last night about ADS-B and my mind went to How the ADS-B system could be used or misused.  Some thoughts I had:

 

1) ADSB Out requires a certified high-precision GPS source.  Not knowing how GPS data is presented out it occurs to me that there is no way for ATC or the FAA to know if you have an actual certified GPS source or not. If my ADS-B enabled transponder is getting a GPS signal, does it know if it's certified or not?  Almost certainly not.  It probably just receives a set of encoded coordinates, and cannot tell if they come from a $3000 certified ADS-B position source, or a Garmin 296 on the glareshield.

 

If an ADS-B source has additional data (for example, extra decimal places to make position data "high precision"), it would almost certainly be possible to place a "converter box" between your crappy old GPS and your transponder to convert the signal to a format acceptable to the ADS-B system.  

 

For example, let's say your old 296 outputs a latitude of 34.95 degrees, but ADS-B requires four decimal places of precision for valid "high precision" data.  It would be trivial to make a converter dongle to add two random digits to the back of the position data, so 34.95 becomes 34.9526, and now the ADSB system is happy, and you are still giving reasonably accurate position, just within normal-precision GPS standards.  The "system" has no way to tell the difference.  So you have spent $15 for a pirate GPS dongle instead of $3000 for a true ADS-B GPS source.  Your chances of getting caught in this is very close to 0%.

 

I'm not advocating doing this, just saying there are a lot of cheap-ass pilots out there who might consider this so they could keep visiting controlled airspace.  In fact one could argue that it's a silly decision to spend $5000+ on a real ADS-B system for your two-stroke Kitfox you paid $11k for. 

 

 

2) ADS-B data will certainly be used for intercepts.  Bust airspace, and your ADS-B identifier and position data will be transmitted in real time to intercepting aircraft.  They can find you right quick.  No problem really, you broke the President's silly TFR and you MUST BE STOPPED.  One can argue that.  But at some point it will be drones doing the intercepts.  And all that same data could also be passed directly to a GPS-enabled missile, which tracks your exact position in real time, flies close to your location, then activates its terminal guidance to hit your airplane.  It can't hit the wrong airplane because it's keyed to your ADS-B identifier and comparing what it is locked on to with the GPS data you are giving it right to impact.

 

Some will say that these kinds of systems are great, providing necessary national defense against the Bad Guys [tm].  But given the current paranoid (IMO) national security stance of the government, it is certainly a valid concern.  In the Boston Marathon bombing, the police instantly locked down the city, harassed citizens, and did door-to-door searches of entire neighborhoods, with no warrants.  Is it really unthinkable that in a true warfare or mass terrorist scenario, somebody might say "we have six planes in the area, and we can't tell if one of them is a terrorist plane...shoot them all down" ?  Or if they ground all air traffic like on 9/11, but you don't get word and go fly (or are already in the air)?  Just something to consider.

 

 

3)  The data.  NSA is collecting essentially all mobile phone and tablet data in the USA.  Phone calls, texts, data streams, photos, all of it to be able to reconstruct a "picture" of any citizen's movements, contacts, and activities.  It is 100% certain they will be collecting and storing ALL ADS-B data as well, on every aircraft everywhere in the USA.  After all, that amount of data is trivial in size compared to mobile phone data, and already in the hands of the feds, it's low-hanging fruit.

 

Remember the CBP airplane stops on the flimsiest of pretexts to attempt to intimidate pilots into allowing their aircraft to be searched.  You can bet they will be feeding all ADS-B data into computer models of behavior to find, stop and harass anybody that "fits the profile" of a drug runner, terrorist, child molester, exotic animal smuggler, or somebody who double parks.  Remember that your ADS-B system will be tagged to your aircraft registration; it will be easy for law enforcement to cross-reference the registration data to your complete criminal record, and now with the Affordable Care Act, with your medical records as well.  There will be NO anonymity for pilots ever again.

 

Also, I'd bet the feds argue that ADS-B data is "theirs" and that they can sell it at their discretion to third parties.  That data contains where you fly, how often, at what altitude, etc.  As soon as you land at an airport, you might get a bunch of texts from the local FBO to buy fuel, and maybe oxygen refills too (after all, they know you just flew for three hours at 16,000 feet, you must need more O2, right?).  You will start getting more spam mail and e-mail because your data and habits have been given to anybody willing to buy them.  ADS-B is like a discount shopper card, you get some token benefits (traffic and weather) to convince you to give up your lucrative personal data.  

 

 

These are just a few off the top of my head.  ADS-B services are nice, but the more I think about the system they are building, the more I become convinced that it's not really about safety and traffic separation for the feds, it's more about control.  But some think I'm paranoid.

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You are paranoid  but that's ok because they are out to get you.

 

California balanced its budget on fees and now there are cops with radar guns behind every bush, cameras at every intersections and the cost of citations goes over $1,000 especially when you consider the impact on your insurance premiums.

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If I may state a counter point to #1: the same could be said about current mode C transponders. If someone wanted to get around the system, they can. However, the technical knowledge needed to circumvent is more complicated than just buying an ADS-B Out transmitter.

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Andy, do you ever turn GPS location on on your phone or tablet?

I'm not saying that we're not (myself included) already giving up a lot of our location and personal data. But one of the things I like about flying is the sense of being above and away from all that, and being somewhat anonymous and "unplugged". Knowing that there are people tracking my every movement down to a couple of meters, makes that seem a bit less freeing. Plus my smartphone doesn't have access to every bit of information about me that I ever reported to any government agency. Some of the folks looking at ADS-B will have all of that.

 

Just because we have let our privacy erode to some degree, is not really a good argument for just giving up on it altogether...

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If I may state a counter point to #1: the same could be said about current mode C transponders. If someone wanted to get around the system, they can. However, the technical knowledge needed to circumvent is more complicated than just buying an ADS-B Out transmitter.

Sure, #1 was more just as stand-alone thought I had about how one might get around the 2020 mandate and keep flying in controlled airspace. I know people flying on Mode C transponders than have not had their required calibrations.

 

My point was it might not be more complicated to cheat. All you need to know is the data input that an ADS-B compliant transponder expects from the GPS source, and you could make something to do the translation. There may not even BE a translation; it might just accept any GPS source and presume it's of the correct precision, letting FAA regulations take care of compliance. In that case you'd just hook any GPS to your transponder and pretend to be compliant. Unless you were ramp checked nobody would even know.

 

Again, NOT advocating this, simply a thought experiment.

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There have been some discussions about the weaknesses in the system.  We can only hope they are listening, redesigning, and patching...

http://www.pilotsofamerica.com/forum/showthread.php?t=38211 

http://www.pilotsofamerica.com/forum/showthread.php?t=58560 

http://www.pilotsofamerica.com/forum/showthread.php?t=59569 

tim

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For whatever reason, I was thinking last night about ADS-B and my mind went to How the ADS-B system could be used or misused.  Some thoughts I had:

 

1) ADSB Out requires a certified high-precision GPS source.  Not knowing how GPS data is presented out it occurs to me that there is no way for ATC or the FAA to know if you have an actual certified GPS source or not. If my ADS-B enabled transponder is getting a GPS signal, does it know if it's certified or not?  Almost certainly not.  It probably just receives a set of encoded coordinates, and cannot tell if they come from a $3000 certified ADS-B position source, or a Garmin 296 on the glareshield.

 

If an ADS-B source has additional data (for example, extra decimal places to make position data "high precision"), it would almost certainly be possible to place a "converter box" between your crappy old GPS and your transponder to convert the signal to a format acceptable to the ADS-B system.  

 

For example, let's say your old 296 outputs a latitude of 34.95 degrees, but ADS-B requires four decimal places of precision for valid "high precision" data.  It would be trivial to make a converter dongle to add two random digits to the back of the position data, so 34.95 becomes 34.9526, and now the ADSB system is happy, and you are still giving reasonably accurate position, just within normal-precision GPS standards.  The "system" has no way to tell the difference.  So you have spent $15 for a pirate GPS dongle instead of $3000 for a true ADS-B GPS source.  Your chances of getting caught in this is very close to 0%.

 

I'm not advocating doing this, just saying there are a lot of cheap-ass pilots out there who might consider this so they could keep visiting controlled airspace.  In fact one could argue that it's a silly decision to spend $5000+ on a real ADS-B system for your two-stroke Kitfox you paid $11k for.

 

 

Certainly possible to spoof the data but you'll need much more than a dongle.  The ADS-B data stream is much more than position and none of the Garmin portables provide nearly enough information.  Some of these values are fixed while others are dynamic.  You'd need a decent microprocessor with enough CPU power to keep up with the required update intervals. AC20-165 has a good high-level explanation of the data fields.

 

2) ADS-B data will certainly be used for intercepts.  Bust airspace, and your ADS-B identifier and position data will be transmitted in real time to intercepting aircraft.  They can find you right quick.  No problem really, you broke the President's silly TFR and you MUST BE STOPPED.  One can argue that.  But at some point it will be drones doing the intercepts.  And all that same data could also be passed directly to a GPS-enabled missile, which tracks your exact position in real time, flies close to your location, then activates its terminal guidance to hit your airplane.  It can't hit the wrong airplane because it's keyed to your ADS-B identifier and comparing what it is locked on to with the GPS data you are giving it right to impact.3)  The data.  NSA is collecting essentially all mobile phone and tablet data in the USA.  Phone calls, texts, data streams, photos, all of it to be able to reconstruct a "picture" of any citizen's movements, contacts, and activities.  It is 100% certain they will be collecting and storing ALL ADS-B data as well, on every aircraft everywhere in the USA.  After all, that amount of data is trivial in size compared to mobile phone data, and already in the hands of the feds, it's low-hanging fruit. Remember the CBP airplane stops on the flimsiest of pretexts to attempt to intimidate pilots into allowing their aircraft to be searched.  You can bet they will be feeding all ADS-B data into computer models of behavior to find, stop and harass anybody that "fits the profile" of a drug runner, terrorist, child molester, exotic animal smuggler, or somebody who double parks.  Remember that your ADS-B system will be tagged to your aircraft registration; it will be easy for law enforcement to cross-reference the registration data to your complete criminal record, and now with the Affordable Care Act, with your medical records as well.  There will be NO anonymity for pilots ever again. Also, I'd bet the feds argue that ADS-B data is "theirs" and that they can sell it at their discretion to third parties.  That data contains where you fly, how often, at what altitude, etc.  As soon as you land at an airport, you might get a bunch of texts from the local FBO to buy fuel, and maybe oxygen refills too (after all, they know you just flew for three hours at 16,000 feet, you must need more O2, right?).  You will start getting more spam mail and e-mail because your data and habits have been given to anybody willing to buy them.  ADS-B is like a discount shopper card, you get some token benefits (traffic and weather) to convince you to give up your lucrative personal data. 

Active radar and your Mode C pinpoints your location as well.  The feed from for these intercepts would be the same system that is tracking Mode C.  Mode C doesn't go away in 2020.  Pretty trivial to add a feature to mark the Mode C aircraft in question in front-end.  Would have to do something similar to the TIS-B traffic.

 

There is still the option to output a random ICAO address if squawking VFR.  Once you enter the system (IFR, flight following), you would then be traceable.

 

 

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My Dynon XPNDR is a full  Mode S Class 1 (SV-XPNDR-261) with ADS-B OUT via 1090ES; TIS Traffic Input.

My SV-ADSB-470 is a UAT Band (978 MHz) ADS-B receiver. It can receive traffic and weather.  The FAA ADS-B TIS-B service can see the 1090ES ADS-B out transmission and provides a complete traffic picture.

 

As of the current software version, the SV-XPNDR-261 is certified to TSO C166a. When TSO-C166b

software upgrade for the transponder comes out Dynon promises a firmware upgrade to meet the spec.

 

The SV-XPNDR-261 is compatible the Garmin Aera 796 also installed in the aircraft.

But your Dynon GPS position source is not appropriately certified to be compliant with the 2020 mandate (as per Dynon).

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I have the same setup as "CTLSi" in my CTLSi. really like seeing the traffic around me, and knowing most of the fast kids are seeing my data on their TCAS systems. What it has done for my flying is make me very careful of all control airspace, because I know they can read my N number on their scopes.

 

CTLSi, does your Garmin 796 show the traffic information your getting from the Dynon? Mine doesn't, which may mean I need to turn on the TIS interface on my Garmin 796

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Dynon does list Garmin as a legit input, sir.

Depends on your purpose. The Skyview transponder has 2 source inputs. One is for Skyview the other for a limited number of certified GPS devices specifically Freeflight and the Garmin 430/530 series.

 

The Skyview can accept position output from a variety of GPS devices including Dynon's own. The position data from the GPS in this configuration is included in the data stream that is sent to the Dynon transponder. As per Dynon, this will serve to wake-up the ground stations which will then transmit traffic but is not 2020 certified.

 

Even if a certified GPS feeds the Skyview, you would still need to connect a second interface from the certified GPS to the second port of the transponder to be 'legal'.

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