0:00:00.000,0:00:09.120
silent 30C3 preroll titles
0:00:09.120,0:00:11.950
applause
0:00:11.950,0:00:15.000
Travis Goodspeed: First I need[br]to apologize for typesetting this
0:00:15.000,0:00:20.080
in OpenOffice. I know that the[br]text looks like a ransom note.
0:00:20.080,0:00:24.509
But that’s what happens[br]when you don’t use LaTex.
0:00:24.509,0:00:27.630
I’d also like to give a shoutout to[br]Collin Mulliner if he is here,
0:00:27.630,0:00:29.680
and our Dinosaur rock band.
0:00:29.680,0:00:33.230
laughs, applause
0:00:33.230,0:00:36.870
We’re a Christian rock band, we’re[br]called ‘Jesus lives in the ISS’ and
0:00:36.870,0:00:46.070
we know that he is always watching us,[br]but we think that it’s easier for him
0:00:46.070,0:00:50.199
to hear our prayers when[br]he’s, you know, in an orbit
0:00:50.199,0:00:55.689
that passes over us. So we need to use[br]orbital tracking to know when to pray!
0:00:55.689,0:00:57.749
laughter
0:00:57.749,0:01:00.899
As I’m sure you can guess I’m not[br]recognized as a legal minority religion
0:01:00.899,0:01:06.140
in Germany. I’d also like to thank skytee
0:01:06.140,0:01:11.010
and Fabienne Serrière and Adam Laurie
0:01:11.010,0:01:16.810
and Jim Geovedi for some[br]prior satellite tracking work,
0:01:16.810,0:01:20.350
and the Scooby Crew at Dartmouth[br]College for all sorts of fun
0:01:20.350,0:01:24.689
whenever I bounce out there.[br]This is the mission patch
0:01:24.689,0:01:28.329
of the Southern Appalachian[br]Space Agency (SASA).
0:01:28.329,0:01:33.790
applause and cheers
0:01:33.790,0:01:36.920
This was drawn by Scott Beibin and there[br]are a few pieces of my people’s native
0:01:36.920,0:01:42.610
culture that I need to point out here. On[br]the right the little Dinosaur type thing
0:01:42.610,0:01:48.149
with his finger going out, you might[br]call him E.T. but we call these things
0:01:48.149,0:01:51.530
‘buggers’. They are like this tall, and[br]they are green and that’s why the man
0:01:51.530,0:01:55.990
on the left has a shotgun.[br]laughter
0:01:55.990,0:02:00.909
Because he doesn’t want to be abducted.[br]You got a satellite dish in the middle
0:02:00.909,0:02:04.350
and it’s sitting on sinter blocks because[br]that’s also a piece of my people’s
0:02:04.350,0:02:10.259
native culture. There’s a moonshine[br]still in the background.
0:02:10.259,0:02:15.120
That’s kind of like Vodka but you[br]make it at home and from corn.
0:02:15.120,0:02:19.820
And then there’s the mountain… a piece…[br]it looks like there are snow peaks
0:02:19.820,0:02:24.530
on those mountain tops. But our mountains[br]aren’t tall enough to have snow.
0:02:24.530,0:02:28.679
These are actually that we’ve blown off[br]the lids of the mountains for coal mining.
0:02:28.679,0:02:32.490
Which is another piece of[br]my people’s native culture.
0:02:32.490,0:02:37.001
And at the top, in space you can see[br]the ISS, and you can see a banana,
0:02:37.001,0:02:41.580
and you can see what I think is a bulb.[br]This is to signify space trash.
0:02:41.580,0:02:45.909
I mean there’s a lot of stuff up there.[br]And, you know it’s symbolism that matters
0:02:45.909,0:02:51.260
in these things, you know?
0:02:51.260,0:02:54.729
At BerlinSides, in May of 2012
0:02:54.729,0:03:00.520
I did a lecture on reverse-[br]engineering the SPOT Connect.
0:03:00.520,0:03:05.289
The SPOT Connect is a little[br]hockey puck type thing
0:03:05.289,0:03:08.950
– this is what it looks like.[br]And these things are great.
0:03:08.950,0:03:13.790
It weighs a bit more than your cell phone[br]but it runs off of a couple of batteries,
0:03:13.790,0:03:17.680
it connects to your phone by Bluetooth.
0:03:17.680,0:03:21.840
Originally these were emergency locator[br]beacons. So if you’re going hiking…
0:03:21.840,0:03:24.569
have any of you seen the movie where[br]the guy has to cut off his arm
0:03:24.569,0:03:30.760
with a dull knife? If you’re hiking and[br]you don’t want that same experience
0:03:30.760,0:03:34.349
you buy one of these things. And[br]then there’s an emergency button
0:03:34.349,0:03:38.760
you can push that transmits your[br]GPS coordinates by satellite
0:03:38.760,0:03:44.180
to rescue workers. But that was boring,[br]so they had to add social media.
0:03:44.180,0:03:46.540
laughs, laughter
0:03:46.540,0:03:49.680
So in addition to keeping you[br]from chewing off your own arm
0:03:49.680,0:03:54.920
this device will also allow you to[br]tweet and make Facebook posts.
0:03:54.920,0:04:00.370
laughs, laughter
0:04:00.370,0:04:05.350
The idea is that as you’re running…[br]here I’m crossing the Schuylkill River
0:04:05.350,0:04:10.010
in Philadelphia and the Android[br]phone on the left is making a post.
0:04:10.010,0:04:15.659
And I did an article on reverse-[br]engineering the Bluetooth side
0:04:15.659,0:04:22.430
of these things. Because… I use a weird[br]brand of phone that Microsoft killed off,
0:04:22.430,0:04:27.520
and I’m terribly bitter about it. But[br]I also figured out the physical layer.
0:04:27.520,0:04:34.930
And that’s what this diagram shows.[br]This transmits at 1.6125 GHz.
0:04:34.930,0:04:40.830
And it sends a pseudo-random stream, so[br]each one of these zeros is a long chunk
0:04:40.830,0:04:44.140
where it’s bouncing back and forth[br]between two different frequencies.
0:04:44.140,0:04:48.750
And the same for the ones.[br]But the way that the pattern works
0:04:48.750,0:04:54.551
is that it switches the signal whenever[br]it is going from the 0 signal
0:04:54.551,0:04:59.080
to the 1 signal. And internally, there are[br]these little pops that you can actually
0:04:59.080,0:05:03.910
identify on a software defined radio[br]recording. And this is how you can
0:05:03.910,0:05:08.040
reverse-engineer the signal that[br]the SPOT Connect is sending up
0:05:08.040,0:05:14.510
to its satellite network.
0:05:14.510,0:05:18.330
Everything is clear text on this.[br]And it’s completely unencrypted.
0:05:18.330,0:05:25.040
It just has your serial number, your GPS[br]coordinates, and a bit of ASCII text.
0:05:25.040,0:05:29.759
So if you listen on this frequency and[br]you have the correct recording software
0:05:29.759,0:05:33.630
you can actually watch all of the SPOT[br]Connect messages that are transmitting
0:05:33.630,0:05:39.530
up from your location. And this would be[br]great except that this is designed for
0:05:39.530,0:05:44.490
hiking in areas where there’s no cell[br]phone service. So having an antenna
0:05:44.490,0:05:47.990
on the uplink frequency is kind of[br]useless. You know you would actually
0:05:47.990,0:05:52.290
have to go out to a national park, find[br]some guy who is about to chew his arm off,
0:05:52.290,0:05:55.639
and then you could listen to his uplink[br]where he is like tweeting: “Hey, I’m gonna
0:05:55.639,0:06:00.699
chew my arm off”, you know?[br]laughter
0:06:00.699,0:06:09.810
So that’s great as a proof of concept[br]but it’s not really anything practical.
0:06:09.810,0:06:13.460
The current state of that was that I knew[br]the protocol and I could sniff the uplinks.
0:06:13.460,0:06:17.300
But I wanted to sniff the downlinks. So[br]it’s easy for me to get the thing that
0:06:17.300,0:06:21.509
goes up to the satellite. But what I wanted[br]was what comes down from the satellite.
0:06:21.509,0:06:27.400
And that requires a satellite dish. But[br]a geo-stationary dish isn’t good enough
0:06:27.400,0:06:32.249
because the satellites that run this[br]network – there are a lot of them,
0:06:32.249,0:06:37.710
it’s called the Globalstar network,[br]they fly really low across the earth,
0:06:37.710,0:06:43.289
and they fly across the earth in very[br]tight, very fast orbits. So they’ll move
0:06:43.289,0:06:48.889
from horizon to horizon in 15 to 20[br]minutes. Which means that you either need
0:06:48.889,0:06:53.789
like a sweat shop army of kids[br]trying to aim the satellite dish
0:06:53.789,0:07:01.259
as it’s going across or you need[br]to make it computer-controlled.
0:07:01.259,0:07:04.490
Stepping back from the SPOT[br]Connect for a little bit, and
0:07:04.490,0:07:08.009
discussing some prior research.[br]Adam Laurie did some work
0:07:08.009,0:07:12.099
with geostationary satellites.[br]These are the satellites that stay
0:07:12.099,0:07:16.449
in one position in the sky.[br]He gave two sets of talks
0:07:16.449,0:07:23.740
– one in 2008 and the second in[br]2010. And he used a DVB-S card
0:07:23.740,0:07:28.169
connected to a satellite dish with[br]a DiSEqC motor, so that it could move
0:07:28.169,0:07:34.330
the satellite dish left and right in order[br]to scan a region of the horizon.
0:07:34.330,0:07:37.259
His tool is publicly available,[br]it’s called satmap.
0:07:37.259,0:07:41.289
You can grab it at this URL.
0:07:41.289,0:07:46.130
And then after he finds a signal he has[br]a feed scanner. Normally when you use
0:07:46.130,0:07:51.270
Satellite TV your provider gives you[br]a listing of the frequencies, and
0:07:51.270,0:07:58.199
your provider gives you an exact orbital[br]position to aim your satellite dish at.
0:07:58.199,0:08:02.330
But Adam’s tool allows you to scan to[br]see which frequencies are in use and
0:08:02.330,0:08:06.949
which protocols are in use, once[br]you’ve correctly aimed your dish.
0:08:06.949,0:08:09.699
And he also describes a technique[br]for moving your dish left and right
0:08:09.699,0:08:15.780
while doing this in order to[br]identify where the satellites are.
0:08:15.780,0:08:19.639
This recording here is from[br]a re-implementation that I made
0:08:19.639,0:08:24.430
of Adam’s work, in order to[br]catch up with it. In this diagram
0:08:24.430,0:08:30.199
the x-axis – because you move left[br]and right – that shows the azimuth,
0:08:30.199,0:08:35.049
that shows how far left or right my[br]satellite dish has moved. And then
0:08:35.049,0:08:40.860
the y-axis shows the frequency. And[br]all of these dots are strong signals.
0:08:40.860,0:08:48.290
So every vertical bar in which you see[br]chunks of frequencies, that’s a satellite.
0:08:48.290,0:08:52.230
But these stay in the same position. So[br]it’s easy for me to repeat this experiment.
0:08:52.230,0:08:56.780
It’s easy for me to re-run it, and to find[br]the same satellites in the same position.
0:08:56.780,0:09:04.700
It’s easy to debug this.[br]But it can’t move in elevation.
0:09:04.700,0:09:08.170
This diagram is actually[br]a very small slice of the sky.
0:09:08.170,0:09:14.450
We’re looking at a single line,[br]maybe 10 degrees across.
0:09:14.450,0:09:17.750
Maybe only 5 degrees across.
0:09:17.750,0:09:22.690
So hacking Ku-band – the television[br]satellites – has the advantage
0:09:22.690,0:09:27.420
that you can use cheap standardized[br]hardware. I bought one of these DVB-S cards
0:09:27.420,0:09:33.520
in Mauerpark, in Berlin for 3 Euro. You[br]can use standardized DiSEqC motors,
0:09:33.520,0:09:37.270
you can buy them at a satellite TV shop.
0:09:37.270,0:09:42.020
TV signals come with video feeds[br]so you can actually see pictures.
0:09:42.020,0:09:45.580
There was a scandal about 4..5 years[br]ago where they were finding
0:09:45.580,0:09:50.350
drone [control] feeds that were being[br]bounced across these satellites.
0:09:50.350,0:09:56.890
In the nineties it was very popular to[br]listen to the sort of unedited sections
0:09:56.890,0:09:59.910
of interviews, when people would[br]be interviewed over a satellite,
0:09:59.910,0:10:04.910
before Skype and such[br]things became options. And
0:10:04.910,0:10:08.750
there are also networking signals here[br]using TCP/IP packets. So you can actually
0:10:08.750,0:10:13.900
turn your DVB-S card into[br]a promiscuous ethernet adapter,
0:10:13.900,0:10:18.010
and start sniffing all of the traffic that[br]comes across. This is also a great way
0:10:18.010,0:10:23.750
to get free downlink bandwidth. Because[br]you can just flood packets at an address
0:10:23.750,0:10:27.660
that, you know, will be routed to[br]you, or several addresses, and
0:10:27.660,0:10:32.670
then you sniff it out as the[br]legitimate receiver ignores them.
0:10:32.670,0:10:37.100
But it also has some disadvantages. It[br]only works for geostationary satellites.
0:10:37.100,0:10:40.570
If the satellite is not staying in the[br]same position relative to the ground
0:10:40.570,0:10:46.750
then you can’t track it. Your[br]dish also moves very slowly.
0:10:46.750,0:10:50.410
And it only moves left and right.[br]It won’t move up and down.
0:10:50.410,0:10:53.030
And you’re limited to standardized[br]signals. So while it’s great that you get
0:10:53.030,0:10:59.230
video and TCP/IP you’re never[br]going to get anything weird.
0:10:59.230,0:11:05.230
You’re not gonna get any mobile[br]data, you’re not going to get any
0:11:05.230,0:11:10.670
Brazilian truck-drivers – we’ll[br]get to those in a bit. laughs
0:11:10.670,0:11:15.710
I misspoke, you actually will get[br]Brazilian truck-drivers in this.
0:11:15.710,0:11:19.360
So I bought a satellite dish. One of the[br]best things about living in America is
0:11:19.360,0:11:25.530
that you can buy industrial[br]hardware cheap as dirt on ebay.
0:11:25.530,0:11:29.190
I know things aren’t likely used to being[br]a cat bite to (?)(?) human children anymore.
0:11:29.190,0:11:33.400
But this satellite dish here on[br]the left – the one in the radome –
0:11:33.400,0:11:40.980
that’s my dish. And to the right,[br]that’s the boat that it came from.
0:11:40.980,0:11:49.890
applause[br]laughs
0:11:49.890,0:11:53.770
This came from a military ship.[br]But the dish itself is also available
0:11:53.770,0:11:57.620
for civilian use on very large yachts.
0:11:57.620,0:12:01.750
The dish itself is a Felcom 81 and it[br]was intended for use with a network
0:12:01.750,0:12:08.210
called Inmarsat. Inmarsat allows[br]for telephone connections,
0:12:08.210,0:12:12.890
and also data connections when you’re on[br]a boat. So if the crew wants to call home
0:12:12.890,0:12:18.010
or wants to go to AOL Keywords
0:12:18.010,0:12:23.530
or whatever was popular back when[br]this was common they could do that.
0:12:23.530,0:12:28.420
And the dish was designed to sit[br]at the very top of a ship’s mast.
0:12:28.420,0:12:31.660
The reason why is that at the top of[br]the mast there aren’t any obstructions
0:12:31.660,0:12:35.360
– it has a clear view of the sky in all[br]directions. But there’s a complication
0:12:35.360,0:12:39.230
with being on the top of the mast. Which[br]is that the ship is rocking beneath you
0:12:39.230,0:12:43.860
and you’re moving more[br]than the rest of the ship.
0:12:43.860,0:12:47.880
So they have stepper motors[br]for azimuth, elevation and tilt.
0:12:47.880,0:12:52.800
And then they have spinning gyroscopes.[br]Back before the iPhone there was
0:12:52.800,0:12:57.950
this dark, dark time when[br]gyroscopes actually spun.
0:12:57.950,0:13:01.900
And this is the sort of gyroscope that[br]it has. It actually has 4 of them so
0:13:01.900,0:13:05.670
that it can measure its movement.
0:13:05.670,0:13:10.940
And then it has a control computer. So the[br]idea is that the dish itself can be moved
0:13:10.940,0:13:15.620
while remaining absolutely stable[br]with regard to the gyroscopes.
0:13:15.620,0:13:20.000
So it compensates for the rocking of[br]the ship beneath it as it’s targeting
0:13:20.000,0:13:27.530
a stationary satellite.[br]In America this costs 250 dollars
0:13:27.530,0:13:32.080
but it’s electronics equipment, so while[br]you think that would only be a 180 Euro
0:13:32.080,0:13:40.080
it’s more like 2500. And that’s before[br]import duties and it being impounded.
0:13:40.080,0:13:44.680
We also have this lovely culture in which[br]people love excuses to use their trucks.
0:13:44.680,0:13:50.600
So the guy that I bought this from offered[br]to deliver it to my home for only $200.
0:13:50.600,0:13:57.340
It was an 11-hour drive.
0:13:57.340,0:14:00.330
But if you wanted this you’d have to[br]bring it back in your carry-on luggage
0:14:00.330,0:14:05.500
and that could be awkward.
0:14:05.500,0:14:09.490
I got this dish and I decided I had[br]to do something with it. So I created
0:14:09.490,0:14:15.040
the Southern Appalachian Space Agency.[br]I’m from the state of Tennessee,
0:14:15.040,0:14:19.520
formerly known as the State of Franklin[br]until North Carolina invaded us.
0:14:19.520,0:14:22.270
It’s ok, I know Europeans suck at history.
0:14:22.270,0:14:30.310
laughs[br]laughter and applause
0:14:30.310,0:14:33.180
Now I’m trying to think of how to show[br]you on a map where Tennessee is
0:14:33.180,0:14:36.930
without having a map. But, you know,[br]it’s okay, I know you suck at geography
0:14:36.930,0:14:39.750
and will forget it soon. (?)
0:14:39.750,0:14:41.550
From audience: It’s very[br]near Texas, to the north.
0:14:41.550,0:14:48.471
Travis: Texas is our first colony. But[br]it’s actually a decent drive to the east.
0:14:48.471,0:14:53.470
Due east (?). You don’t[br]actually have to go it anyways.
0:14:53.470,0:14:57.990
So what I did was I took these motors[br]which were designed to be able to move
0:14:57.990,0:15:03.250
the satellite dish to compensate[br]for the rocking the ship and
0:15:03.250,0:15:09.550
I re-purposed them to track through[br]the sky while the ground is stable.
0:15:09.550,0:15:12.580
We don’t have very many earthquakes in[br]Tennessee. The last one that we had
0:15:12.580,0:15:18.310
made rivers run the wrong direction.[br]But it’s okay – it’s a geography thing.
0:15:18.310,0:15:22.060
laughs[br]So this allows me to track things
0:15:22.060,0:15:26.500
that are moving through the sky.[br]But it doesn’t actually matter
0:15:26.500,0:15:30.330
where they’re moving in the sky because[br]that’s just a software problem.
0:15:30.330,0:15:35.540
So in addition to tracking objects that[br]are in low-earth orbit by a software patch
0:15:35.540,0:15:41.770
I can also track things that are in deep[br]space. It’s not much harder to track
0:15:41.770,0:15:47.830
deep space probes or stars than it[br]is to track items in low-earth orbit.
0:15:47.830,0:15:52.640
And then I added a software defined radio[br]which allows me to record a signal now
0:15:52.640,0:15:57.920
and then demodulate it later.[br]Which is necessary if you intend
0:15:57.920,0:16:02.810
to reverse-engineer a signal. Because[br]a lot of the downlinks from these satellites
0:16:02.810,0:16:07.630
are completely non… completely[br]undocumented. And being able
0:16:07.630,0:16:11.220
to tune in to the right frequency is only[br]half of it. You also need a recording
0:16:11.220,0:16:15.510
of sufficient quality that you can[br]reverse-engineer it after the fact.
0:16:15.510,0:16:19.680
We’re sort of spoiled by software[br]defined radios in that when doing
0:16:19.680,0:16:27.220
software defined radio work we usually[br]have a very good signal to work from.
0:16:27.220,0:16:33.610
So having high quality signals for later[br]reverse-engineering is necessary.
0:16:33.610,0:16:39.310
I really wanted to be able to identify[br]undocumented downlinks for low-earth orbit
0:16:39.310,0:16:44.310
in the same way that we already[br]do this for geo-stationary orbit
0:16:44.310,0:16:49.990
using tools like the ones that Adam[br]Laurie and Jim Geovedi made.
0:16:49.990,0:16:54.500
So I built a software framework as[br]a collection of Python daemons.
0:16:54.500,0:16:58.720
And these run across a home[br]area network in my house.
0:16:58.720,0:17:03.780
There’s a Beaglebone inside of the Radome.
0:17:03.780,0:17:09.539
And an x86 server in the house. Or AMD64,[br]whatever the kids call it these days.
0:17:09.539,0:17:13.230
And then I used Postgres for coordination.[br]So that all of these daemons can talk
0:17:13.230,0:17:19.290
to each other without… without me really[br]caring which machine they’re on.
0:17:19.290,0:17:25.969
So for maintenance I can have my[br]laptop pretending to be the dish,
0:17:25.969,0:17:30.790
and I can have stepper motors on my desk,[br]and I can watch them spin, and I can even
0:17:30.790,0:17:35.010
make a model of the dish and swap these[br]components in and out without the rest of
0:17:35.010,0:17:42.700
the network being confused. This also[br]allows for SQL injection attacks to
0:17:42.700,0:17:48.260
physically move my dish. Which is why the[br]sensor network is not on one of those
0:17:48.260,0:17:52.620
fancy WEB 2.0 things. Because of you could[br]inject, say, “UPDATE target SET name=
0:17:52.620,0:17:55.910
‘VOYAGER 1’”. Then my dish would physically[br]move and start tracking Voyager 1
0:17:55.910,0:18:01.440
through the sky. Voyager 2
0:18:01.440,0:18:07.190
doesn’t actually come into the sky because[br]of my position in the Northern hemisphere.
0:18:07.190,0:18:11.170
So, it’s okay, I know you suck at[br]geography. But Voyager 1 is going up,
0:18:11.170,0:18:15.440
and Voyager 2 is going down.
0:18:15.440,0:18:19.260
There’s a Realtek software defined radio[br]for the radio reception. Although
0:18:19.260,0:18:24.370
these things are garbage. So I’m in the[br]process of replacing this for the HackRF.
0:18:24.370,0:18:29.760
There’s also an EiBot board for motor[br]control. We’ll get back to that in a minute.
0:18:29.760,0:18:34.560
And there’s an Inertial Measurement Unit[br]from VectorNav which actually measures
0:18:34.560,0:18:39.510
using the fancy MEMS gyroscopes and[br]a MEMS compass how I’m moving.
0:18:39.510,0:18:44.700
This isn’t accurate enough to target[br]the dish, so I’m still counting steps
0:18:44.700,0:18:49.830
to move the dish. But it is accurate[br]enough to tell me when my belts
0:18:49.830,0:18:56.520
have broken. Or when I’m up[br]against a physical obstruction.
0:18:56.520,0:19:01.510
This is skytee helping[br]me out with the dish.
0:19:01.510,0:19:04.950
He’s zip-tying it. Because, you know[br]we know everything about duct tape
0:19:04.950,0:19:07.260
where I come from, but we don’t know[br]anything about zip-ties. So I had
0:19:07.260,0:19:10.920
to bring in a German engineer.[br]laughter
0:19:10.920,0:19:14.270
We call him a gerry wigger(?)[br]but, you know…
0:19:14.270,0:19:20.020
This is the satellite dish itself. And you[br]can sort of see in this photograph
0:19:20.020,0:19:25.420
where we’ve strapped on the equipment.[br]There’s like an umbilical cord.
0:19:25.420,0:19:29.700
Or more like a spinal column that actually[br]runs up the back of the dish. So we just
0:19:29.700,0:19:36.820
added new cables onto that line.[br]And then zip-tied them in place.
0:19:36.820,0:19:42.390
And skytee came up with all these[br]crazy ideas like that we should use
0:19:42.390,0:19:46.570
chains and zip-ties to make sure that the[br]cables don’t tear themselves out. And
0:19:46.570,0:19:51.890
that worked tremendously well in practice.[br]So, as this thing spins around,
0:19:51.890,0:19:57.680
by the original design there’s a ring[br]connector that all of the signals
0:19:57.680,0:20:01.220
go through. That all of the networking[br]goes through. That all of the rest
0:20:01.220,0:20:05.680
goes through. And that worked in the[br]nineties because it had no reason
0:20:05.680,0:20:11.310
to send anything faster than 9600 baud.
0:20:11.310,0:20:18.050
But with the modern signals going across[br]it I need 100 MBit/s or even GB ethernet,
0:20:18.050,0:20:22.290
that’s not enough, I need more than[br]two wires. So there’s a cable that comes
0:20:22.290,0:20:25.290
across it, and then I rely on the[br]software to keep it from wrapping
0:20:25.290,0:20:31.180
that cable around itself. So it can only[br]move, say, 400 degrees around.
0:20:31.180,0:20:34.730
But that’s still more than a full circle.[br]So by stopping halfway and moving back
0:20:34.730,0:20:39.710
I can prevent it from getting snagged.
0:20:39.710,0:20:43.400
We’ve got the Beaglebone on the left,[br]in the middle there’s a USB hub
0:20:43.400,0:20:47.550
and on the right is the motor controller.
0:20:47.550,0:20:52.640
The Beaglebone runs Debian Linux and[br]takes care of sending the software defined
0:20:52.640,0:21:00.220
radio recordings over the network. It also[br]takes care of updating the motor positions
0:21:00.220,0:21:06.210
to be the ones that the database[br]declares should be current.
0:21:06.210,0:21:13.060
The stepper motors themselves are the[br]originals that the dish was designed with.
0:21:13.060,0:21:17.810
And they’re running to an EiBot Board.[br]The EiBot board was intended
0:21:17.810,0:21:24.560
for plotting on Easter eggs[br]laughs, laughter
0:21:24.560,0:21:27.740
I feel, you know… is that neat?
0:21:27.740,0:21:32.830
laughs[br]applause
0:21:32.830,0:21:37.750
So you can actually aim a satellite dish[br]that’s as tall as you are, with of these
0:21:37.750,0:21:42.470
fancy motors using less sophisticated[br]equipment than what’s used
0:21:42.470,0:21:47.330
in a 3D printer. Don’t panic, though.
0:21:47.330,0:21:51.360
It’s a hell of a lot more[br]reliable than a 3D printer.
0:21:51.360,0:21:55.420
But we needed some sort of backup in[br]addition to the inertial measurement unit
0:21:55.420,0:21:59.360
telling us when the device[br]had snagged itself.
0:21:59.360,0:22:05.180
It would also help to have[br]a visual queue. Because
0:22:05.180,0:22:09.810
the satellite dish sits in Tennessee, and[br]while I love my home town, and, you know
0:22:09.810,0:22:15.170
I’m very proud of being Tennessean, it’s[br]also a long way to travel when you need
0:22:15.170,0:22:20.830
to re-orient the dish. Using an[br]accelerometer it’s easy enough
0:22:20.830,0:22:26.120
to correct the elevation. Because you can[br]use the accelerometer as a level, and
0:22:26.120,0:22:31.220
you can use that to tell how high up the[br]dish is pointing, at an absolute scale.
0:22:31.220,0:22:38.370
But the compass isn’t very accurate. So[br]instead, as a backup we have a webcam
0:22:38.370,0:22:44.300
that’s taped to the top. Taping[br]is my people’s native culture.
0:22:44.300,0:22:47.710
We have it taped to the top, and then[br]it’s pointing backwards. So this gives us
0:22:47.710,0:22:52.280
like a rear view camera,[br]from the dish’s position.
0:22:52.280,0:22:57.179
So as the dish sits[br]inside of its radome…
0:22:57.179,0:23:00.920
– junk cars in the yard are also[br]my people’s native tradition!
0:23:00.920,0:23:04.340
laughs, laughter
0:23:04.340,0:23:09.670
So the dish sits there next to[br]my brother’s Toyota Supra.
0:23:09.670,0:23:13.770
And that thing, you know,[br]that thing flies as soon as it gets
0:23:13.770,0:23:17.800
an engine put back in it.[br]laughter
0:23:17.800,0:23:21.860
So it sits there and it’s moving but[br]externally you can’t see where it is.
0:23:21.860,0:23:26.019
Which means that I can’t call my family[br]in Tennessee and blackmail them into
0:23:26.019,0:23:29.620
– yet again – looking at my dish to tell[br]where it’s pointed. There are bolts
0:23:29.620,0:23:32.882
that hold this down, it takes half an hour[br]to remove the lid, another half an hour
0:23:32.882,0:23:37.390
to put it back on.
0:23:37.390,0:23:43.230
So instead we took the radome…[br]that’s Frank, he’s my cat.
0:23:43.230,0:23:45.500
Give a “Cheers!” for Frank!
0:23:45.500,0:23:51.500
applause and cheers
0:23:51.500,0:23:56.460
Yeah, we had such a great time with Frank.[br]And we never knew that she was pregnant.
0:23:56.460,0:24:02.950
If you happen to need kittens and wanna[br]pay the customs fees I’ll hook you up!
0:24:02.950,0:24:10.580
So then we took tape and ran tape[br]down the edges of the radome,
0:24:10.580,0:24:15.090
and then marked it. So from the markings[br]you can tell which clock position
0:24:15.090,0:24:20.230
the back of the satellite dish is pointing[br]at. So if you point the dish towards 12:00
0:24:20.230,0:24:25.870
you know that you’re roughly at 6:00,[br]so you know that it’s pointing South.
0:24:25.870,0:24:29.110
And then you can sort of scan the sky[br]for a stationary target, and navigate
0:24:29.110,0:24:32.950
off of that, to recover your position.
0:24:32.950,0:24:39.620
Software-wise… remember, the[br]whole thing runs through Postgres,
0:24:39.620,0:24:45.750
so I just tunnel the Postgres over SSH,[br]and then I wrote a Python client
0:24:45.750,0:24:52.120
that displays the satellite positions[br]and the satellite state in PyGame.
0:24:52.120,0:24:54.820
This is intended for making those games[br]where you see the rabbit and the rabbit
0:24:54.820,0:25:00.550
jumps on the other rabbit. But it… works![br]And it works perfectly well enough
0:25:00.550,0:25:04.940
to target the dish. Because all that this[br]software has to do is plot the positions
0:25:04.940,0:25:10.570
of the satellites, and give orders back to[br]the database when I click on a satellite
0:25:10.570,0:25:15.270
or click on a position.[br]It can also display stars.
0:25:15.270,0:25:21.350
So the red items are satellites which are[br]not selected. The green item is GOES-3
0:25:21.350,0:25:25.470
which is the satellite that I’m targeting.[br]And then the white items are
0:25:25.470,0:25:32.140
stars in the sky. Now this is[br]a plot in which the azimuth
0:25:32.140,0:25:37.230
is on the X axis, and the elevation is on[br]the Y axis. But I can also arrange it
0:25:37.230,0:25:42.160
into a polar plot. Which sort of gives me[br]an upside-down view of the satellite dish
0:25:42.160,0:25:47.520
looking at the sky.[br]I doubt you can read it but
0:25:47.520,0:25:55.330
just above the green circle in the center,[br]that’s Polaris which is the North star.
0:25:55.330,0:25:58.770
It’s also weird because, you know,[br]working on this, you know, I thought
0:25:58.770,0:26:02.170
that I got really good at astronomy[br]until I realized that I only knew
0:26:02.170,0:26:07.940
what the stars looked like during the day.[br]laughter, laughs
0:26:07.940,0:26:12.010
And it being PyGame you can[br]actually run it on a mobile device.
0:26:12.010,0:26:17.960
So the same client that runs on my[br]laptop can also run on my Nokia N900.
0:26:17.960,0:26:26.140
laughs[br]applause
0:26:26.140,0:26:32.940
A significant portion of the GUI client for[br]this was written while stuck on the U-Bahn,
0:26:32.940,0:26:38.330
connected over 3G, SSH through[br]and just using emacs on the phone.
0:26:38.330,0:26:44.590
laughter, laughs[br]applause
0:26:44.590,0:26:49.270
If you’re one of those people who needs to[br]complain about the N900 being too old,
0:26:49.270,0:26:54.260
it also runs on the N9.
0:26:54.260,0:26:59.020
And then you can take the data out of this[br]and run it through scientific software.
0:26:59.020,0:27:03.100
In addition of the software defined radio[br]recordings themselves being dumped out
0:27:03.100,0:27:09.720
to a text file or a binary file on disk[br]you can also dump out things like
0:27:09.720,0:27:14.590
the received signal strength indicators[br](RSSI). So this is a screenshot in which
0:27:14.590,0:27:18.340
I’m identifying different satellites that[br]I’ve seen in the sky based upon
0:27:18.340,0:27:23.040
their downlink signal peaks. You can see[br]the noise floor there, at the bottom,
0:27:23.040,0:27:28.320
and then there’s a rather strong signal on[br]the left. And a weaker, narrower signal
0:27:28.320,0:27:34.780
on the right. Now, the[br]daemons that build this up…
0:27:34.780,0:27:38.400
you need an orbit prediction daemon.[br]Because you need to know
0:27:38.400,0:27:41.490
where the satellites are and where[br]they’re going, and where they will be
0:27:41.490,0:27:45.830
by the time you get to them.
0:27:45.830,0:27:50.760
You need to update the orbits themselves.
0:27:50.760,0:27:55.150
LEO satellites are described in TLE files,
0:27:55.150,0:27:58.191
these are called ‘Two Line Entry’ and[br]they’re called ‘Two Line Entry’ because
0:27:58.191,0:28:01.970
they’re three lines long.[br]laughter
0:28:01.970,0:28:07.610
These were originally used by NORAD for[br]inter-continental ballistic missile tracking.
0:28:07.610,0:28:11.251
And because a ballistic missile[br]is basically in orbit, it’s just that
0:28:11.251,0:28:14.980
that orbit happens[br]to collide with the earth.
0:28:14.980,0:28:20.380
But this format isn’t terribly accurate[br]for satellites that adjust their own orbit.
0:28:20.380,0:28:26.930
So anything that has fuel, or has engines,[br]or changes mass will vary its position.
0:28:26.930,0:28:34.160
And this also doesn’t account for drag.[br]Because, you know, the missile itself,
0:28:34.160,0:28:38.200
you know it goes up it goes down, it’s[br]not orbiting enough for the light drag
0:28:38.200,0:28:43.030
in the upper atmosphere to matter. But for[br]a satellite it does. So these Two Line Entries
0:28:43.030,0:28:47.760
will work for a matter of days or maybe[br]a couple of weeks. But they don’t last
0:28:47.760,0:28:55.090
longer than that. So you need a daemon[br]that grabs the new files from Space Track.
0:28:55.090,0:28:57.971
And this is just a matter of like[br]a recursive WGET, and then
0:28:57.971,0:29:02.880
parsing the files. And that still needs[br]to be done. You also need motor control,
0:29:02.880,0:29:06.780
because you need to move the dish[br]physically to track your target.
0:29:06.780,0:29:10.600
You need input for the Inertial[br]Measurement Unit. This comes over
0:29:10.600,0:29:15.240
a low voltage serial port. And then[br]you need radio daemons to handle
0:29:15.240,0:29:20.590
spectrum analysis or downlink recording.[br]And these you’ll have several of them,
0:29:20.590,0:29:29.040
you have to swap them out. So you’ll begin[br]by using the spectrum analyzer to identify
0:29:29.040,0:29:33.730
that your aim is accurate, that you’re[br]accurately tracking the targets
0:29:33.730,0:29:37.630
well enough to get a recording from[br]them. And then after that you begin
0:29:37.630,0:29:42.130
to take software defined recordings off[br]them. And, eventually, you might have
0:29:42.130,0:29:48.130
a standalone application that parses[br]what you’re receiving. Such as
0:29:48.130,0:29:55.550
the Osmocom guys did with OpenGMR.
0:29:55.550,0:29:59.810
So for orbit prediction I began[br]with a DOS program that had been
0:29:59.810,0:30:04.550
ported to Unix, called PREDICT.
0:30:04.550,0:30:10.360
And this worked, but it’s garbage.
0:30:10.360,0:30:16.070
It only supports 20 satellites plus the[br]sun, the moon, Venus and Mars.
0:30:16.070,0:30:24.460
But no other planets because it’s[br]designed for astronomy photographers
0:30:24.460,0:30:28.800
who want to get a picture of something[br]as it comes over the horizon. You know,
0:30:28.800,0:30:33.890
I need to track hundreds of targets and[br]then write a script to opportunistically
0:30:33.890,0:30:37.640
pick the ones that I want to record.[br]Because otherwise you have to like
0:30:37.640,0:30:44.880
set an alarm clock for the half-hour pass[br]in which you can play with something.
0:30:44.880,0:30:48.900
That software does allow you to query the[br]results by UDP, though. So you can just
0:30:48.900,0:30:55.000
send it a flood of request packets,[br]then it will flood back with the data
0:30:55.000,0:31:00.860
you’re looking for. So I switched to[br]a library called PyEphem which allows you
0:31:00.860,0:31:05.960
to track hundreds of birds. It has no[br]UDP nonsense. It will also calculate
0:31:05.960,0:31:12.940
satellites, planets and stars.[br]And the really nifty thing about this
0:31:12.940,0:31:18.090
is that you tell it… you know, it being[br]a library you tell it when to update
0:31:18.090,0:31:23.030
the individual object that you’re[br]interested in. So you can update
0:31:23.030,0:31:26.710
objects that are out of view or[br]uninteresting more slowly
0:31:26.710,0:31:33.300
than the ones that you care about.[br]So I managed to track every single item
0:31:33.300,0:31:39.230
in geo-stationary orbit. This thick[br]ring here is the Clarke Belt
0:31:39.230,0:31:47.000
of all satellites in geo-stationary orbit,[br]as viewed from my Southern horizon.
0:31:47.000,0:31:53.880
applause
0:31:53.880,0:31:58.460
The Two Line Entry files you can get[br]freely from CELESTRAK.COM.
0:31:58.460,0:32:02.370
So this is just a simple script that[br]grabs them and then inserts them.
0:32:02.370,0:32:06.990
And the prediction daemon will actually[br]select them as it is loading up.
0:32:06.990,0:32:14.010
Because all inter process communication is[br]running through this Postgres database.
0:32:14.010,0:32:16.540
And this daemon can be moved to[br]a different machine if I needed
0:32:16.540,0:32:21.730
more computing power, or anything[br]like that. The motor control demon…
0:32:21.730,0:32:27.470
well, the EiBot board is designed to take[br]stepper motor commands. It shows up
0:32:27.470,0:32:33.429
as USB Serial device on Linux. So as[br]I plug it in to the Beaglebone it appears
0:32:33.429,0:32:41.660
as /dev/ttyACM0. And the baud rate doesn’t[br]matter. Because this is a USB device.
0:32:41.660,0:32:48.810
You could then send it simple commands.[br]Like ‘SM,3000,500,-400’ means that I wanna
0:32:48.810,0:32:55.559
move a stepper motor for 3000 ms. I want[br]the first motor to move 500 forwards,
0:32:55.559,0:33:03.330
that’s UP, and the second one to move[br]400 LEFT which is backwards 400 steps.
0:33:03.330,0:33:07.540
And then it will count that out, and[br]then it sends me back an OK.
0:33:07.540,0:33:11.981
If I want to disable the motors, I send[br]‘EM,0,0’. This allows the motors to be
0:33:11.981,0:33:16.429
freely spun. Because normally a stepper[br]motor will physically hold its position,
0:33:16.429,0:33:22.500
you need to turn them off in[br]order to slide the dish around.
0:33:22.500,0:33:28.260
‘EM,1,1’ will enable both motors[br]in 1/16-of-a-step mode.
0:33:28.260,0:33:31.340
Stepper motors can do fractional[br]steps because they’re
0:33:31.340,0:33:37.800
holding themselves in position.
0:33:37.800,0:33:41.390
You can see the motors themselves[br]with the belts and the gear train.
0:33:41.390,0:33:46.800
This thing on the right would probably[br]be illegal for me to turn on.
0:33:46.800,0:33:53.100
The thing on the right is a 250 W[br]amplifier. laughter
0:33:53.100,0:33:58.780
The stepper motors themselves just have[br]six wires. In a lot of 3D printer type stuff
0:33:58.780,0:34:02.690
they ignore the middle two. So you just[br]drop off the middle two wires, you run
0:34:02.690,0:34:07.100
the other four to your stepper[br]controller, and you’re good to go.
0:34:07.100,0:34:10.079
The belts and stuff need to be measured[br]in order to figure out exactly
0:34:10.079,0:34:16.639
what the gear reduction is. Because you[br]need to know how many steps form a degree.
0:34:16.639,0:34:23.250
The IMU unit, this Vectornav VN100,[br]it’s a MEMS gyroscope and accelerometer
0:34:23.250,0:34:28.380
and a compass in a single box.[br]It costs $500 which was
0:34:28.380,0:34:33.780
more than all of the other[br]equipment put together.
0:34:33.780,0:34:37.280
The compass is confused by the stepper[br]motors because the compass is measuring
0:34:37.280,0:34:40.280
magnetic fields. So you need to[br]mount this physically as far away
0:34:40.280,0:34:46.159
from the stepper motors as possible. And[br]the gyroscope is confused by motor jerk
0:34:46.159,0:34:50.310
which is a shame because stepper motors[br]work as a series of jerks rather than
0:34:50.310,0:34:56.510
as a single consistent motion. And the[br]accelerometer is confused by gimbal lock,
0:34:56.510,0:35:00.880
so you have to switch it to[br]a quaternion mode in order to get
0:35:00.880,0:35:05.640
consistent values out of it. And if I had[br]to do this over again I’d really try
0:35:05.640,0:35:10.610
to drop this piece of garbage. But it’s[br]a lovely technology when it works.
0:35:10.610,0:35:12.310
some laughter
0:35:12.310,0:35:19.010
Now for position calculations: the[br]elevation itself comes from the IMU,
0:35:19.010,0:35:24.160
the azimuth comes from the motor daemon.[br]This is because the accelerometer
0:35:24.160,0:35:29.710
can very accurately tell which way[br]the earth’s gravity is pulling it
0:35:29.710,0:35:34.410
whereas the accelerometer has to integrate[br]jerks over time in order to figure out
0:35:34.410,0:35:38.890
its position. So the[br]accelerometer will drift
0:35:38.890,0:35:46.410
and the compass will be confused by the[br]magnetic fields while the elevation is
0:35:46.410,0:35:53.300
just a single accelerometer[br]that doesn’t drift.
0:35:53.300,0:35:59.760
And the IMU will become[br]a backup for these things
0:35:59.760,0:36:03.480
in order to figure out how to make[br]it reliable. But at the moment
0:36:03.480,0:36:09.100
the position measurement is infinitely[br]more reliable. The tilt motor
0:36:09.100,0:36:13.970
I’m not using at present because on[br]a ship that’s rocking it’s necessary
0:36:13.970,0:36:20.290
to tilt the dish. On a satellite dish[br]that’s staying still the only useful
0:36:20.290,0:36:26.280
tilting the dish is so that you can follow[br]the arc of a satellite through the sky
0:36:26.280,0:36:30.020
by only moving a single motor.[br]Photopgraphers do this when they’re
0:36:30.020,0:36:35.210
trying to get long exposures of moving[br]satellites. At the moment my software
0:36:35.210,0:36:39.180
doesn’t support this feature. But[br]if it turns out to be necessary
0:36:39.180,0:36:43.960
to get higher quality[br]recordings I might add it.
0:36:43.960,0:36:47.430
There are radio daemons. The[br]first is a spectrum analyzer.
0:36:47.430,0:36:51.480
This just measures the signal strength[br]on each frequency. And it does it by the
0:36:51.480,0:36:58.230
power spectral density function.
0:36:58.230,0:37:02.900
And the strength itself will[br]vary with the position error.
0:37:02.900,0:37:07.050
So this allows you to figure out how[br]far off you are by sort of testing,
0:37:07.050,0:37:09.690
by overshooting just a little bit,[br]or undershooting just a little bit
0:37:09.690,0:37:15.170
to center on your target. The downlink[br]recorder dumps the IQ values
0:37:15.170,0:37:19.950
in the software defined radio[br]directly to an NFS share,
0:37:19.950,0:37:24.749
which can later be decoded and[br]read and reverse-engineered.
0:37:24.749,0:37:30.260
We’ve got a whole table of spectrum[br]data. And then I plot that in a tool
0:37:30.260,0:37:36.840
called Viewpoints which NASA releases[br]for dealing with giant scatter plots
0:37:36.840,0:37:44.480
in multiple dimensions. Each view takes[br]two dimensions, and it’s tons of fun.
0:37:44.480,0:37:47.570
The client GUI is this PyGame. I have[br]Postgres for communications, and
0:37:47.570,0:37:51.590
the server does all the heavy lifting,[br]so the Beaglebone itself never has
0:37:51.590,0:37:58.260
to do anything complicated with[br]regards to software defined radio.
0:37:58.260,0:38:03.610
This is also about these faint blue lines[br]are positions at which I’ve seen
0:38:03.610,0:38:09.620
particularly strong signals in order to[br]identify which satellites are active
0:38:09.620,0:38:14.190
and which ones are inactive.[br]Because satellites die over time.
0:38:14.190,0:38:17.920
And particularly useful targets we’re[br]reverse-engineering are satellites that are
0:38:17.920,0:38:22.910
out-of-commission or outdated.[br]I’m running out of time by these markers.
0:38:22.910,0:38:24.930
Does that mean that we’re skipping[br]questions, or does that mean that
0:38:24.930,0:38:28.910
I need to be off the stage?[br]mumbling to stage
0:38:28.910,0:38:35.880
Not having Q&A, okay. So today I get[br]accurate tracking of satellites.
0:38:35.880,0:38:41.020
And this thing can run unattended 24h[br]a day for months without maintenance.
0:38:41.020,0:38:46.030
Like I said: it’s nothing like a 3D printer.[br]laughter
0:38:46.030,0:38:49.970
It takes software defined radio[br]recordings, it can provide maps
0:38:49.970,0:38:54.920
of views of different[br]satellites in the sky.
0:38:54.920,0:38:59.920
The next step is I want to publish[br]a ‘port scan’ of the entire sky.
0:38:59.920,0:39:04.460
So which frequencies are in use on which[br]birds, for every bird that ever comes
0:39:04.460,0:39:08.490
above Tennessee, on every[br]downlink that fits my antenna
0:39:08.490,0:39:12.230
as well as a database of software[br]defined radio recordings. If anyone
0:39:12.230,0:39:19.000
would care to donate a truckload[br]of disks – that might be handy.
0:39:19.000,0:39:23.080
I’d also like to make other ground[br]stations. The software that I’ve written
0:39:23.080,0:39:25.910
ought to be portable to new hardware.[br]So there’s nothing that should keep you
0:39:25.910,0:39:30.950
from being able to port this to run on[br]your own dish. And I have a large yard,
0:39:30.950,0:39:36.530
so I could conceivably have[br]a dozen of these things.
0:39:36.530,0:39:38.910
Another way that you can do it, and[br]the way that it’s traditionally done
0:39:38.910,0:39:45.230
for, say, cube satellites is having[br]Yagis or other loosely directional antennas
0:39:45.230,0:39:48.910
in order to receive the signals.[br]I went with a dish because I wanted
0:39:48.910,0:39:54.920
more selectivity. I wanted to be able to[br]get reverse-engineerable recordings
0:39:54.920,0:40:03.020
rather than intentional ones for which[br]I already knew the downlink protocol.
0:40:03.020,0:40:07.990
So this is my van, my van is amazing.
0:40:07.990,0:40:15.620
applause
0:40:15.620,0:40:19.300
Thanks to Nick Farr. I had a bit too[br]much to drink in Montreal and
0:40:19.300,0:40:24.440
I called Nick Farr and I said: “Nick,[br]I want a DUKW”, like these amphibious
0:40:24.440,0:40:28.500
troop transport vehicles. And Nick[br]said: “Sorry, I can’t get you one but
0:40:28.500,0:40:32.000
you want a news van!” And I said:[br]“Hell yeah, I want a news van!”
0:40:32.000,0:40:35.430
So – this pole in the background, that’s[br]not a lighting pole. That’s actually
0:40:35.430,0:40:43.369
part of the van.[br]laughter
0:40:43.369,0:40:49.590
This is the antenna retracted. This mast[br]goes up 20 m by pneumatic power.
0:40:49.590,0:40:55.180
There’s an air compressor in the back.[br]Here is the control panel,
0:40:55.180,0:40:57.880
there’s an air-conditioned[br]office in the middle.
0:40:57.880,0:41:02.480
laughter, laughs
0:41:02.480,0:41:08.910
This has four 19" server racks as well[br]as some A/V equipment that was left over.
0:41:08.910,0:41:14.100
I was particularly excited about the[br]video monitor which supports PAL
0:41:14.100,0:41:18.460
which you folks are familiar with,[br]NTSC or “Never The Same Color”
0:41:18.460,0:41:21.840
which is my people’s native culture…[br]laughter
0:41:21.840,0:41:25.610
But most importantly, it does SECAM,[br]the system essentially contrary
0:41:25.610,0:41:29.530
to the American method.[br]laughs
0:41:29.530,0:41:34.230
laughter and applause
0:41:34.230,0:41:41.130
So in addition to my radio equipment[br]I’m adding my Soviet PDP-11 which was…
0:41:41.130,0:41:45.360
laughs[br]…and that’s not a joke. I have a Soviet
0:41:45.360,0:41:51.540
PDP-11 thanks to the kind folks at the[br]Positive Hacking Days conference.
0:41:51.540,0:41:58.200
This is the control panel,[br]and that’s my talk!
0:41:58.200,0:42:13.340
applause
0:42:13.340,0:42:17.740
Herald: Thank you so much.[br]There actually is time for Q&A now.
0:42:17.740,0:42:20.672
Travis: Well, first I’d like to introduce[br]you to my cat. If we could go back
0:42:20.672,0:42:25.691
to the prior image. This is Frank![br]We didn’t know it at that time, but
0:42:25.691,0:42:31.570
Frank was not dad (?) when this picture was[br]taken. If you’d like kittens get in touch!
0:42:31.570,0:42:34.800
Okay. Are there any questions?
0:42:34.800,0:42:39.030
Question: Great talk. What’s the most[br]interesting signal you decoded so far?
0:42:39.030,0:42:44.650
Travis: At the moment I’m sort of stuck[br]at the L band range. Because of filters
0:42:44.650,0:42:48.220
that I have yet to remove. So everything[br]gets attenuated, and becomes annoyingly
0:42:48.220,0:42:54.720
quiet outside of the 1.5 ..1.6 -ish range.
0:42:54.720,0:43:00.210
The Globalstar network is what I’m[br]most interested in targeting next.
0:43:00.210,0:43:03.050
I can’t wait to see what[br]people are tweeting
0:43:03.050,0:43:07.029
while they should be enjoying nature.
0:43:07.029,0:43:08.850
Herald: Is there a question[br]from the internet?
0:43:08.850,0:43:12.890
Signal Angel: Yeah, the internet has[br]many questions. So first one was:
0:43:12.890,0:43:18.430
Is there really no authentication or[br]encryption on the Q band IP services?
0:43:18.430,0:43:24.859
So you can just spoof at will? And…
0:43:24.859,0:43:28.540
can the birds see the physical[br]location of the source
0:43:28.540,0:43:34.650
accurately enough to[br]find who is spoofing?
0:43:34.650,0:43:41.200
Travis: I’m not an expert in Ku band. The…[br]for the downlink the bird has no clue
0:43:41.200,0:43:45.750
as to the location of the dish. Because[br]you’re only listening. They can roughly
0:43:45.750,0:43:49.530
figure out your geographic area because…[br]they need to figure out where
0:43:49.530,0:43:53.590
the spot beam is going. So they might know[br]whether you’re in, say, Germany or
0:43:53.590,0:44:01.720
in France. But they won’t know whether[br]you’re in Heidelberg or Mannheim.
0:44:01.720,0:44:07.420
They do have forms of authentication for[br]many satellite networks. Satellite TV
0:44:07.420,0:44:11.950
is one of the best-protected network[br]services because of the satellite wars
0:44:11.950,0:44:16.580
in the nineties in which TV pirates would[br]fight back and forth with smart card
0:44:16.580,0:44:23.330
designers. But there are also many[br]unencrypted links. And there are…
0:44:23.330,0:44:31.260
because of standard protocols those[br]are particularly easy to find in Ku band.
0:44:31.260,0:44:37.390
Question: You’ve been talking about[br]using RTLSDR from osmocom.
0:44:37.390,0:44:42.470
And you were talking about your spectrum[br]analysis program. Is this one working
0:44:42.470,0:44:45.810
with RTLSDR?
0:44:45.810,0:44:53.970
Travis: So… RTLSDR… so I’m using[br]the RTLSDR, not the OsmoSDR.
0:44:53.970,0:44:58.900
Which are separate. The spectrum[br]analyzer is working with the RTLSDR.
0:44:58.900,0:45:03.230
My complaint about the RTLSDR is that[br]when you have a strong signal next to
0:45:03.230,0:45:08.230
a weak signal the weak signal is[br]utterly useless for interpretation.
0:45:08.230,0:45:13.330
Question: Okay. Thank you.
0:45:13.330,0:45:15.490
Herald: Another question[br]from the internet?
0:45:15.490,0:45:19.180
Signal Angel: Okay, next question from[br]the internet is: How do you record
0:45:19.180,0:45:24.490
the radio signal from the dish,[br]at what sampling rate?
0:45:24.490,0:45:29.890
Travis: The RTLSDR samples at 2 million[br]samples per second. As soon as I switch it
0:45:29.890,0:45:37.250
over to the HackRF I’ll be having[br]20 million samples per second.
0:45:37.250,0:45:41.900
The sampling rate can be reduced once[br]the bandwidth of the signal is known.
0:45:41.900,0:45:46.390
For reduced storage. And the[br]recordings can also be compressed.
0:45:46.390,0:45:53.300
But it’s still a hell of a lot of storage.
0:45:53.300,0:45:54.659
Herald: Any other questions?
0:45:54.659,0:45:57.770
Signal Angel: The internet[br]has more questions…
0:45:57.770,0:45:59.860
Herald: Okay…
0:45:59.860,0:46:04.380
Signal Angel: Did you look into obtaining[br]a capacitive high-bandwidth coupler as used
0:46:04.380,0:46:09.880
for the rotary gantries in CT scanners?[br]Those can apparently transmit contactless
0:46:09.880,0:46:13.420
several GBytes per[br]second, bi-directionally.
0:46:13.420,0:46:16.109
Travis: I’ve not looked into those.[br]It seemed better to have an umbilical
0:46:16.109,0:46:21.820
cable and to be careful not to snap it.
0:46:21.820,0:46:25.630
The whole thing was done for a budget[br]of less than 2000 Dollars, and can be
0:46:25.630,0:46:31.640
recreated for less than a budget of 1000[br][Dollars]. And they… so we tried to avoid
0:46:31.640,0:46:36.140
fancy parts. The local radio shack loved[br]us because we’d swing in and buy all sorts
0:46:36.140,0:46:39.880
of crazy stuff. As soon as we told them[br]that we wanted the satellite dish to
0:46:39.880,0:46:41.300
dance Gangnam style…[br]laughs
0:46:41.300,0:46:48.740
laughter
0:46:48.740,0:46:50.820
in German, strong accent:[br]Danke, gerne!
0:46:50.820,0:46:53.810
applause
0:46:53.810,0:46:56.610
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0:46:56.610,0:47:02.893
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