>>Hi everybody uh, I’m Jason Hernandez. Uh our talk is titled tracking spies in the skies uh as you can see there, that’s a photo of a uh domestic surveillance aircraft. Uh N496ww which uh, is an FBI aircraft.  Uh that was flying over the Phoenix area over the last couple of years.  Um, so again uh about the talk our main focus is on um, law enforcement and aerial surveillance mostly focus on domestic flights. Um so the F, FBI the DEA, um local uh sheriff’s offices and police departments.  Um they’re all operating um fixed wing and, and helicopter aircraft.  Um, with a variety of technology.  Um, Sam Richards is gonna lead off uh with a little bit of discussion of the history of aerial surveillance and um the discovery of the FBI and DEAs um secret fleets.  Um, and then Jerod MacDonald-Evoy is going to talk about some of the technology aboard the aircraft.  Um and then I’ll finish up and discuss uh, some algorithmic ways to, detect aerial surveillance um based on flight patterns.  So, over to Sam.
>>Alright, well thank you again everybody for coming out here.  This is crazy.  Um so I wanna say right away that it’s, this talk it’s a huge topic obviously with ya know tons of different agencies and municipalities and technologies, so this isn’t gonna be all encompassing but we’re going to try to do uh it’s best justice we can to the topic.  Uh so I guess for me it started off a long time ago just interested in all kind of conspiracies really.  Uh the closest one that you can think of with this would be black helicopter conspiracy.  So people were suspecting some sort of government activity with unmarked aircraft flying all over the place, um nobody really knew if there was actually something to it or not.  And it turns out that there was interestingly enough. Um and so the first news report that kind of caught my eye and a lot of people’s attention was from the Wall Street Journal.  Uh just like on a lot of these initial reports it was just talking about 1 individual plane uh and it was pretty obvious that you could assume that it would be doing some sort of surveillance.  And then when Baltimore happened with the Freddie B- uh Freddie Gray protest more people started noticing just a single engine Cessna uh circling at ya know a lot of times it was at night and it was pretty obvious to assume that that was monitoring the protest.  Because the plane wasn’t there before that.  And again, with those articles it was just referencing 1 aircraft, not nothing really confirmed um ya know it wasn’t ever acknowledges publicly by the agencies that were operating the aircraft obviously. And that’s sort of when I started getting involved.   Um, yea.
So, I’ve put a story on medium.com uh initially I was just on my Twitter account.  Um I got a tip from somebody I worked with at Minneapolis International Airport, uh he just sent me a screenshot from flightradar24 and it showed just this plane circling all kinds of like, I think it was Southdale Mall in Minneapolis and other highly populated areas.  So we immediately recognize that it was doing some sort of surveillance there uh and we just all open source information.  We just pulled the aircraft's registration up on uh aircraft 1 dot com and from there, there was a list of 62 planes that had similar registration so that plane in particular was registered to FVX Research.  Which doing just more open source investigating you could see that, that wasn’t a real company.  Um, they weren’t on any Secretary of State websites, there was no legitimate business website or anything like that.  So, at the bottom of that first list we found were 2 aircraft registered explicitly to the Department of Justice. Not behind a front name just explicitly DOJ.  Uh those 2 planes were actually 737’s.  So not kind of aircraft that are used for spy planes but still it was, it was interesting to see that correlating right away.
Uh and then from there using just the names of these companies we couldn’t prove existed uh, I just started searching all those specific names like PSL Surveys, FVX Research, um Northwest Aircraft Leasing CO is one of my favorites. And putting those names into these little aircraft registration websites the list ballooned to over 100 aircraft and this was in May of 2015.  So I put that list on Pastebin uh which I’m sure people are familiar with, it’s just like a website you can dump information on and share it.  Uh so at that same time I just put a little brief, ya know write up, like hashtag FBI sky spies, this is probably what’s going on.  Here’s some links to images from flight radar where you can see these planes circling.  Uh and it was all over the country, like, the, Seattle was really have at that time. But basically, anywhere there was a metropolitan area that’s bigger, like bigger than a medium sized city.  Um but also rural places too, like remote places.  Greeley, Colorado outside of Denver was a really small town that was popular with the FBI at that time.  And you can go next. 
So this was basically my main concern with these planes.  Um, I knew about this program from a PBS documentary.  Basically the, the drones in this case they, they patched together what are equivalent to just a ton of cellphone cameras and you make, you an image so large that you actually just, you keep these drones parked over for a long time and then you can see everything moving including people walking, cars and things like that.  Uh and so in the in the war efforts they were using these to try and track down who placed an IED somewhere after the bomb exploded.  And they would literally just review the footage and find where that person went.  And then presumably the special forces or whatever would raid that house.  And so that, that was publicly known uh developed by DARPA in the early 2000s and that was, when I saw planes flying over the country I immediately thought of this technology.  And so, that’ that’s a huge fear obviously if you have everybody in a city being surveilled with all their movements being tracked.  Um so a little bit more on that technology after on probably, but back to the stories. 
So, after I put up my story on medium dot com with, it was just like less than 1,000 words.  Um the ai- the associated press broke that story into the mainstream about a week later.  Uh and so those tweets with the, the flight tracking information and the medium blog post were going viral still.  Uh so that was interesting.  Uh they actually linked to it in the AP article initially.  Uh they called it speculation, which didn’t really hurt my feelings that much.  But let’s see here.  So continuing on to the research.  Um we basically found this office at the FAA’s uh FOIA headquarters. And you can, you can submit a ton of tail numbers.  They were actually r- incredibly responsive and helpful.  This one came from a FOIA that I sent over 700 tail numbers to them.  And they came back with just a massive spreadsheet and n- not much time at all.  And uh you can kinda see the basic info.  Like the tail numbers are highlighted. You see the dates.  Um the airports, cities that they took off and landed at.  But not, not a whole lot of information.  Uh so y- you don’t see the circles or if it was just a simple A to B flight.  But you get a general idea.  And so that, that was helpful but still sort of limited you know?  If we’re gonna go about trying to investigate these things just doing it manually on a flight radar website or doing it through public records requests it's very labor intensive.  Um, and with 100s and 100s of these aircraft which are actually proliferating down from, you can hit the next one.
Um, or maybe the next one, we’ll go back to this one.  SO you can see that these, these companies that are making this technology it’s, it is an industry. It’s surveillance industrial complex.  Uh initially everything starts off with the war efforts it seems and then it eventually percolates down from there from federal to state to local.  And, the bottom there it says, large city law enforcement, medium city law enforcement.  That’s a huge market share.  So we’re gonna clearly see this type of stuff continue to be, ya know even just some podunk sheriff will eventually have a Cessna.  Um, with whatever capabilities so we need more people to look into it.  Cause you looking at one plane, if you pull it up on flight radar, it you’ll see just a bunch of flights right? And that’s, that’s obviously labor intensive so, I think people need to start taking it um taking it seriously. And kind of try to inquire more with whoever is operating the aircraft in their neck of the woods. Um so you want to go back to that open?
This is really interesting to me.  So this was actually made by homeland securities geospatial intelligence team. And you know you can see the red areas.  I’m not sure how clear it is on the screen over there but that’s where there was civil unrest.  Uh the Freddie Gray protest response basically. And then they have all the other critical infrastructure that they’re interested in protecting.  But, so this this wouldn’t’ really be possible without some sort of spy plane over head.  Uh you feed this down and obviously it’s a huge benefit for any law enforcement or intelligence to have a pretty accurate and up-to-date map of an entire city and all of the activity at the time. Um, and then you wanna go and, yeah. 
>>So uh, I’ve been looking into um what the types of different aircrafts through public records. And through public records we’ve been able to and just watching ya know flight radar we’ve been able to determine what types of aircraft they use.  The most common for airborne aerial surveillance are the small fixed wing Cessnas.  It’s like 1 engine prop plane you probably have seen them around. They’re really popular with like flight schools or private owners. Um but they’ll, they’ll fly those around um all over.  A lot of law enforcement has those both local and state and federal. Then the next type of aircraft, these large dual engine beechcraft.  It kind of looks like this, this plane right here but instead of 1 engine up front it’s got 2 on each wing and it can hold about 15 to 20 people.  Now when they got to the state legislator and ask for money to buy these they usually say, oh it’s going to be for transport or things like that or you know moving investigators around the state.  But they when you go through the records you find that they do have surveillance equipment installed on them as well. And they’re using these large engine planes um specially customs and borders patrol has one that they fly up and down the border almost daily uh around Arizona and Texas.  Just running surveillance on the border picking up radio signals and things like that. 
Then there’s the military style plane the Pilatus.  Uh very, very few law enforcement has these, have these.  Uh Phoenix PD is one of the early adopters uh that we know of.  And what’s interesting about these, this specific plane it’s the Specter model which was initially designed for the US Air Force to fly uh and do surveillance in Iraq and Afghanistan.  Now the other interesting thing about this plane is first it’s the largest 1 engine prop plane you can buy and it’s also pressurized. Now if you have a pressurized cabin you can go up way higher and this plane is usually flying at around 17,000 feet.  Doing circles um like 10 mile orbits following some guy or, or looking at a residence.  Um, these are, these are becoming more and more popular.  This is about a 4.5 million dollar aircraft though. So that the, the larger cities are gonna be the ones that are gonna be more interested in the Pilatus.  But the small wix- fixed wing cessnas, I mean there’s not a huge barrier to entry for those for a lot of other local law enforcement because for example the Mary Copen county sheriff’s office down in Arizona, they got one of their panes through Rico.  Uh because there was a guy who was smuggling marijuana on a plane.  They found him, took the plane decided, hey let’s use this for our own uh benefit. 
So the other type of aircraft most people are familiar with uh with when it comes to police aircraft are helicopters, but they’re loud they’re noisy, they’ve gotta fly them low.  They mainly use them for the guy who ran away on foot.  Or to survey like a car accident.  Now drones are still very new to law enforcement. Not very many are using them. Sheriff Joe out in Arpaio petitioned to try and get a predator drone but that never went through obviously. Thank goodness, um but uh eh, eh there’re other law enforcement agencies that are getting like the quadcopters. They’re saying they’re trying to use them for search and rescue but we haven’t really found any uh examples of them being used for surveillances yet and they’re a little bit harder to keep track of.  But law enforcement are getting a lot more interested in those especially with the ones that are backpack deployable.  Um now equipment wise the most popular type of camera system they’re on practically all of these air craft, is the Wescam by L3 Communications now um, the Wescam is interesting, they have 3 different varieties.  Uh they have the MX10, MX15, and MX20.  MX10 uh has like about a 70 time zoom ratio. It’s usually on like the helicopters, because the helicopters don’t have to go very high. Uh MX15 is kind of an in between for your law enforcement agency that can’t ya know spend 1.5 million dollars on a camera system. Um and then the MX20 is though the most popular.  The MX20 is the same camera system that is used on the predator drones.  Um, they have a laser designator where they can uh well on predator drones the laser des- designator is used for missiles.  But on a law enforcement aircraft they use that laser designator to, say they’re following a, a guy who stole a car. They lock it on that car and then the camera doesn’t ya know, the operator doesn’t have to worry too much about moving it and they’re just doing zoom or changing the lens.   Cause you can see it’s got like several different lens, lenses here. And one of those lenses usually is an infrared camera.  FLIR or for looking infrared, um the company that makes those is called FLIR and they’re, they’re the most popular and FLIRs interesting uh because it’s basically, imagine predator vision, that’s what it is.  It’s seeing heat.  Um and it can actually see usually, it can even see through walls and you can see people walking inside a home with the, with their heat signatures.  But um there was a supreme court ruling Danny Lee Kyllo vs the United States which ruled that using uh infrared to look into someone’s home is, it, it requires a warrant. So this guy he was, he was growing pot in his house and police u looked into his house and saw there was a lot of heat coming from the garage and then they said to the judge oh we think that means he’s growing marijuana in there and got a warrant. 
Well Danny Lee Kyllo and his attorneys argued that the, the use of that infrared technology to see into his home constituted a search.  Um, and so they won that and now they, police have to get warrants to use infrared in that, that type of way.  But it’s hard to track to see how police are using that because a lot of time cases that the aerial surveillance is used on, um they’ll seal the dockets.  Now cell site simulators are the other ar- uh type of equipment that we know has been used on these, these aircraft. The FBI’s done it at least twice that we know of.  Now cell site simulators, it’s a little device if you don’t’ know coactively they’re called Stingrays or IMSI catchers and they act like a cellphone tower.  So if there’s one in this room right now everyone’s phone would go to that instead of the cell tower. And they could scoop up the data. Read metadata on the more advanced versions they could even turn it into a passive listening device. They get they can follow where you’re going um and it’s a really popular device.  Um but if you can imagine flying one of those above a city of 1.5 million or so you’re gonna be sweeping up a lot of data uh from that plane.
Now the fourth thing that we have seen on these planes are what they call LETC devices.  Now this is a stupid little acronym they like um that we found from uh, from records.  From FFA records, on, on their airworthiness.  They, airworthiness records y- you can get, they’re public record and it shows everything that’s been installed on an airplane. Um and we found it on several the aircraft it will say installed LETC antenna.  LETC stands for law enforcement technical collection, um and when I reached out to customs and border patrol about the, the myriad of law enforcement technical collection antennas they had installed on their plane they said that they use them to collect signals across the electromagnetic spectrum.  Well.  [laughter]  Electromagnetic spectrums a pretty big place right? So I asked them about that and they just said, no we collect across the entire electromagnetic spectrum which is  ya know x-rays, gamma rays, cell phones, everything.  So what we can assume they are using it, especially customs and border po- patrol probably listen to drug runners with radios or cell phones.  Or even internet signals could be picked up with an LETC uh antenna.  Uh but that’s one we don’t know a whole lot about yet.
Now some examples of use are um, uh one of the most well known uh examples was when the FBI flew their airplane in support of the Baltimore police department during the uh Freddie Gray protest.  Uh this is a screenshot from that, they were using IR uh and they were, they circled I think the protest I think for like 8 to 10 hours that day.  Uh the released all the footage after myself and several other reporters kept bugging them about the footage because we knew it was their plane.  Uh so that’s 1 example of use even though the FBI publicly said that they don’t surveil protests, um but obviously, they did here but they say that’s because they were in support of Baltimore police department and they had asked for that. So that’s the other thing is the FBI will often lend this aircraft out to the local law enforcement that might not have it. 
Now another example was the FBI also did some aerial surveillance of uh this suspect um in Arizona who they believe had been shooting a gun at cars on the interstate 10 out there.  They flew up and down the, the freeway, followed him to his work, circled his work then circled his apartment uh then the next day they arrested him. So we can assume that they were probably getting intelligence on ya know how does he go into his house, what does he drive, where is he driving, who is he seeing? Before they went in with the SWAT team and got him.  Now phoenix PD recently used their military style aircraft to follow a guy who had stolen a U-Haul and led police through uh the city.  Um, and that’s another example of it being used. So it’s even been used in, in smaller crimes like that and not just major investigations.
Now the planes they use front companies.  Sam talked a lot about that. The FBI, FBP, DOJ they’re the main ones that use front companies. Local law Enforcement doesn’t really do that. But we still don’t’ know what’s on those planes.  But there’s a 10 dollar records request that I encourage everyone here to do and we will put a link to how to do this if you’re curious about an aircraft. It’s 10 dollars, they send you a CD the next week and it comes with the airworthiness and registration history for the plane for its entire history and you can look through and see what’s been installed you can see it changing hands. An example is, this plane here uh I’d saw it doing weird patterns near the border and it belonged to this Global GEO Mapping Inc who I couldn’t find any information on anywhere.  They just had a PO Box registration in Albuquerque.  I get the registration uh CD in the mail look in it, look at it, literally the first page it says, you know registrated, registration access, or address PO Box in Albuquerque but physical address Kirtland Airforce Base, customs and border patrol.  So you can, it’s pretty easy to find these planes once you kind of start learning that um, but now they’re getting they’re catching on and we have this problem with Delaware where in Delaware you can register your aircraft to uh like ev- the Delaware Corporation Commissions Office uh and it just becomes a black hole and you can’t get any information. 
Uh for example the Delaware Corporation Commissions Office has over 2,000 planes registered to that building. Um including Google’s Ash Floyd LLC which is their front company for their drone program.  Uh that they’re using to eh look at using drones to deliver things or uh update their maps.  And they have about 10 hummingbird drones registered to the Delaware Corporation Commissions Office.  Um so that’s another new trick that they’re using.
Now this video real quick, this is of the Pilatus uh aircraft in Phoenix following a guy who had stolen the U-Haul.  You can see there that the, they changed lenses because they have about 3 different lenses.  They were orbiting about 17,000 feet 10 miles away. And as you can see um, it’s pretty clear, you can get in really close with this camera and this is a very compressed version of the video they gave me.  So I imagine even on, probably on their version the clarity is even better and you can probably read the license plate, see what state is on the side of the U-Haul and what mural they have.  Um and right here you can tell that they’re starting to designate the U-Haul with the laser designator there. In order to better track it.  Um, now we’re going to skip forward just a little bit here. See there they changed the lens again and in a second here it will go to IR, the infrared and so you’ll get to see a little bit of what that does.  Not sure why they went to IR on this, it was a clear day so, uh they might of just wanted to get some good footage but you can see that, you can see the heat from the, from the road from the car, um and it’s, it’s you can a lot of great information for them, or they get a lot of great information with that system.
Um, now I’m gonna kick it over to Jason.
>>Um, hi everybody again. Um, so we’ve discussed some ways to track down surveillance flights by uh following the paperwork uh documentation, registration, but I wanna look at how we more generally detect surveillance activity.  Um, registrations can be changed and obscured. We’re seeing government agencies get a little bit more clever about how they register aircraft and, and use shell companies.  Um, eh, it’s also um possible that contractors start to get more involved in surveillance.  Uh some surveillance technologies are commercially available. Uh as the technology improves more and more will and you could see um corporations conducting more surveillance, um you could ever see wealthy private individuals funding and, and uh conducting surveillance.  Um and then there’s also kind of a, a big question we’ve, we’ve talked all primarily about the United States but um how much of this surveillance activity is happening in other parts of the world?  Um, are agencies in the UK, in Europe, in other developed countries, or, or even uh the developing world conducting aerial surveillance of this type?  And uh, if they aren’t um when will then?
Um, so I’m gonna discuss some, some techniques to, to filter out surveillance flights.  Um based on taking advantage of knowledge about the, the technical and operational requirements that dictate relatively unique flight patterns.  Um, and as you can see there, um that flight pattern doesn’t look like somebody uh going, going on a commercial flight.  That’s um, kind of this odd cork screw patterns and then you can see there’s a really heavily defined circle there and um whoever is at the center of that circle should probably get a lawyer. [off mic question] Possible. Yeah. [off mic comment]
Okay, um so the question becomes how, how do we track aircraft. So as a hobbyist or an individual radar is not a practical way to, to track aircraft.  But fortunately most aircraft are equipped with transponders that uh beacon a signal, uh with a unique identifier that’s uh actually internat- internationally unique.  Uh is- issued by the International Civil Aviation Organization.  Um the protocol is called automatic dependent surveillance broadcast or ADS-B. Um and it’s just how a beaconing signal.  Uh and positions of aircraft can be calculated uh with the technique called multilateration. Uh that’s where you compare the time difference of arrival for messages that um arrive at multiple receivers. Um you need 4 or more receivers to calculate positioning of a transmitter with multilateration.  Uh obviously more receivers gives you a little bit better fix and better data. Uh and there are some websites and aggregator networks that collect feeds from ADS-B receivers and uh calculate out aircraft positions.  Um some aircraft also transmit uh additional information, they’ll transmit they’re latitude and longitude as calculated by their GPS unit, um squat codes, and uh altitude.  Um but we can’t necessarily rely on the accuracy of the uh positions transmitted by the aircraft so uh multilateration is really helpful in confirming that from multiple sources. 
So, uh the question becomes how do we get a hold of ADS-B data at scale?  Uh fortunately there’s already a large and active community of radio and aviation and hacking enthusiast that collect ADS-B data and um send it to aggregator networks.  Um, all that you need is a Raspberry Pi even your old model 1B that you might have in the closet will work.  Um an RTL-SDR radio, which is a little software defined radio you can buy one for 25 dollars uh over in the vendor area if they’re not out.  Um and antenna of varying size and quality um and an internet connection.  And um so for under 100 dollars you can pick up uh transmissions um from aircraft.  And uh there are multiple aggregator networks that collect ADS-B data and, and calculate positions.  Uh couple of the big ones, Flightradar24 dot come and Flightaware dot com. And I’ll talk more about ADS-B exchange dot com uh which is a bit unique.  Um and uh the FAA regulations require an increasing number of aircraft to transmit ADS-B, it's’ just part of their next gen program to revamp uh air traffic control systems.  So, by 20 20 most aircraft are uh supposed to be equipped with ADS-B out.  Um and then there’s similar regulations around the world um in the EU, India, Australia, etcetera.
Okay but there are some challenges and limitations to the uh availability data.  Um, the major commercial flight tracking sites augment their data with FAA radar data.  Um the FFA gives you this data for free but you have to accept restrictions. And the, and the restriction is that uh tracking sites don’t publish the positions of aircraft that are on their block list.  Um and any aircraft owner can request that their aircraft be added to the block list for free.  Um and even if the tracking site um is picking it up over ADS-B or some other method, they’re, they’re not allowed to publish it.  Um so the commercial sites um, have some restrictions there.  Um, also bulk access to data is uh, limited or expensive if you, it’s not practical to get all of the data for all flights in real time from um these commercial sites.  Um but AD ADS-B exchange is an exception.  Uh they explicitly do not use FFA data and they don’t censor flights.  Um they also provide free access to live and historical data.  Um, I encourage anybody who uses that data to, to donate to them. They don’t endorse us but uh we are big fans of their work, so. 
So, um to pick surveillance flights out of that live streaming data um, there there’s a bit of work that has to be done. Um, there are over 80,000 flights a day.  Uh the uncompressed data coming from ADS-B exchange works out to about 10 gigs a day.  Um and at any given time there’s 8,000 to 13,000 aircraft being tracked in the air.  Usually most of these are not surveillance flights.  Um and so the question becomes how do we pick out the surveillance flights? 
So, um looking at surveillance flights versus other flights uh we know most non-surveillance traffic goes from point A to point B as quickly and efficiently as possible.  Um and commercial traffic and, and most other traffic will try and minimize flying over populated airspace. Populated areas um so commercial airlines have noise restrictions, they are not allowed to fly too low over particular areas.  Uh and then furthermore uh if you’re in a metro area there are lot of different airports including generally a large commercial airport and each of these airports has their own ring that’s controlled air space at different levels. So, this is a screenshot of um the airspace around Phoenix Sky Harbor airport.  Um and you can see that bowtie pattern is the main, main area of controlled airspace, um around the approach for the runways of sky harbor.  Uh and there are different altitude indicators that show that you can’t fly below this range or above this range without getting clearance from the tower.  So, that’s um that’s a hassle for, for a leisure pilot or a commercial travel. They want to get up and out of controlled airspace um as quickly as possible and not have to go in holding patterns, etcetera. 
So and then we also know from um, some of the, the technical information ’bout the equipment on board there are technical and operational constraints for running surveillance flights.  There’s an altitude sweet spot in that if you’re flying too low you’re going to make noise and you’re going to be much more noticeable. Um you also have to deal with controlled airspace from smaller regional airports, um terrain, uh other challenges. On the other side of the coin um most of these aircraft are not pressurized and so they can’t really get much higher than 10,000 feet and they’re not, not built for that.  Um, they also would have to deal more so with uh airspace, controlled airspace from, from the major commercial airport in the area.  Um and then just as 1 example, piece of equipment um cell site simulators, um have a range of approximately 2 miles in a metro area.  Um according to some documents published by the intercept that may improve a bit but it gives you a good guideline in terms of um range.  And if the aircraft is too high you’re going to limit that range on the ground geometrically. 
Um also surveillance flights typically take off and land at the same airport.  It just would get more costly and more impractical if you were trying to schedule surveillance flights between different airports and um so for example in Phoenix uh, the FBI uses the Deer Valley airport, uh which is conveniently about 5 to 10 minutes away from the field office there.  Um, furthermore most surveillance is interested in people that live in densely populated metro areas.  So, these flights are going to be corkscrewing around um over cities, not going straight from ya know Las Vegas to New York, etcetera.  And then there’s some other, other aims, so aircraft capabilities.  Certain aircraft fly too fast it wouldn’t’ be practical to use a 737 to conduct surveillance over, over a city because it just would move too quickly you wouldn’t have much dwell time over the city, aside from costs.  Um, but then the aircraft can’t be too small because they need to generate enough power or carry uh batteries to operate this relatively energy hungry surveillance equipment.  Um they also need to be large enough to carry these relatively large surveillance pods.  So, um, there’s kind of a, a sweet spot in terms of size of aircraft as well. 
So, um with some of that information being considered um, I’ve worked on just a prototype of a, a surveillance score.  So, where you look at the behavior of aircraft and you um try and thin it out as surveillance or not surveillance.  Um, the main metric that I’m using is just calculating 90 degree turns um so that’s where, where the heading of the aircraft changes more than 90 degrees and each time that happens you, you just increment the score.  Um, most commercial traffic is going to only have a couple of turns, maybe to make final approach.  Um, and that’s all conditional based on altitude so again we, we know that there’s generally a sweet spot for, for altitude so um, turns and activity that are in that, that range are scored higher.  Um, lower flying flights might be somebody in a flight school that’s practicing takeoffs and landings.  Um, higher up it might be a, a commercial jet that’s um in a holding pattern before coming in.  So, and then there’s some, some a lot of other uh angles to, to further improve uh detection. So considering the proximity to airports and controlled airspace might help filter out more, um more flight schools. Uh and then uh scoring based on the aircraft model, again we, we have a pretty good idea there, there’s a good list of aircraft that are popular for surveillance and, and well, well built for that purpose.  And so scoring those higher is, is another angle to, to highlight uh surveillance activity. 
Um, also I think that uh it’s suspicious to request that your plane be on the block list and so I would highlight those as interesting, uh potential surveillance aircraft. Um a little bit more geometry might help to filter out survey activity which can sometime trick, trip this um basic turn counting.  Um and then uh comparing flights to interesting geography will, will also highlight uh surveillance activity.  So, for example Jerod found some flights that went, uh up and down along the Arizona uh US Mexico border.  Um so highlighting the border as a interesting geographic area uh will help, help to uh pick out surveillance flights because there’s not really any other reason that somebody is going to fly the length of the US Mexico border.  Um also events like protests, uh the Freddie Gray protest, the protests at the shooting of Jamar Clark, Dakota access pipeline protest. We’ve all seen aerial surveillance and so some scoring of, of those interesting areas might be another angle to, to highlight and uh spot spy planes. 
So, just looking at, at that crude metric of counting the number of 90 degree turns. Um, most flights with 30 or more turns look like surveillance flights.  In that when you start to dig into the paperwork you look where it’s registered, you look at airworthiness documents um a large share of those aircraft are surveillance. Um so this is just an example screenshot of a uh, aircraft over Baltimore during the Freddie Gray protest. 
So, um the prototype code that I’m going to release after the talk is um, takes data um, in a real time live stream from ADS-B exchange and it um, holds it into virtual radar server.  Um ADS-B exchange has a real-time API.  Um that, that V- VRS works this.  And virtual radar server then provides a JSON endpoint that you can grab bye snippets from. Um the reason why I’m using that angle is that um ADS-B exchange also offers historical data that’s in that same JSON format.  So in the future could take that historical data and um use pretty much the same methodology and work on refining the score and uh spotting historic surveillance events.
Um, so that’s just loaded into a queue um split across multiple threads that can be uh, distributed across multiple machines so that’s helpful. Um, should 1 start to analyze um a large archive of historical flight data you spin out virtual machines and uh just kind of crank through it.  And then that’s all queued up. Um it’s composed in redis which has some really nice geo hashing features.  Um and uh the surveillance flights are dumped out as JSON files into uh, a web map so you can look at it on the web. And see these aircraft are, are highlighted as surveillance, or suspicious at least. 
Um and then it also um archives the files into mongoDB so you can do some geo queries and, and look at it um further. And do retrospective analysis. So maybe uh the surveillance score algorithm you want to improve it and tweak it and the reprocess all of your old data and see if anything else falls out.  Um so that’s the idea there.  And this will all be open source.  The um, the white boxes are, are code that I’m releasing.
Um, so here’s an example, screenshot of, of the web map uh this is actually a very new aircraft. It was purchased by the California highway patrol uh circling over the Sacramento area.  You can see uh it kind of does some, some loops and corkscrews and then it goes around different areas.  I think this might actually be um, looking for speeders.  Uh I don’t’ know if anybody’s driven through California and they have these signs, speed monitored by aircraft.  I didn’t really believe it until um, looking at the data a bit more.  So, um. 
So, um if you’re interested in this and wanna work on tracking spy planes there are a lot of things you can do.  Um, it’s pretty easy to set up an ADS-B receiver for less than 100 dollars.  Um a good little weekend project and feed data to ADS-B exchange dot com.  Um, you can donate to ADS-B exchange um they don’t endorse us but uh you can also donate to us.  Um, the code will be open as well so you can use fork and improve the application. It’s still very much a prototype but um it does highlight interesting planes.  Um, so if you have questions um, or wanna see more information you can go to our website uh we’re gonna have a, um some links and article up uh hopefully later today once we get online. Um and links to Github soon.  Thank you.  Um. [applause] 
>>Thank you.  [applause]