Guys, I’m picking up alien signals out
here! Nah, I’m just kidding we’re tracking weather balloons and I’m gonna show you how to do it an Ontario County nonprofit Hey guys, Tory here from Overlook Horizon.
This is an LMS-6 radiosonde and it’s launched by the National Weather Service
twice a day from 100 stations all across the US and you can track these
things they’re pretty easy and it’s kind of cool to find them. The radiosonde here
it’s got a couple of things on the outside those are the weather sensors
here we got humidity sensors temperature sensors there’s a pressure sensor on the
inside there’s also a GPS and a radio transmitter and that’s the cool part
because there’s a radio transmitter you can actually pick up the radio signals,
decode them, figure out where this thing is, how high it is and where it lands and then go pick it up! Now, with that radio transmitter that’s on the inside of the
package the National Weather Service is able to obtain all the information from
the radiosonde during this flight without having to recover them but that
also means that there are radio signals that are out there that’s being
transmitted that anybody can pick up, decode and figure out where this radiosonde is. Now, you can do this at home it’s a fun little project. You can follow
along with a flight, see what kind of peak altitude it gets to and you can
also follow it all the way to landing and then go pick it up. Now, with the LMS-6
radiosonde those radio signals transmit at 1680 megahertz now that’s plus or minus a few megahertz
because there are four channels that they can possibly transmit on so they
start at 1676 they have a channel at 1678, 1680
and 1682 megahertz. Now you can either email your local upper air observation station and try to find out exactly what frequency they use on a
regular basis or you can just try them out there’s only four of them so it’s
pretty easy to identify which one is being used and they don’t always use the
same one it’s pretty typical for them to use the same one over and over again but
if there’s a special observation going on they may change it up they may use a
different frequency so you may have to check all four frequencies anyways to
find out if that particular flight is using that particular frequency. If
you’re gonna try to track one of these things, the first thing you got to do you got
to figure out where it’s being launched from… where’s the closest upper air
observation station that’s nearest you go to
you can find a map of all the National Weather Service upper air stations
across the U.S. If you’re not in the US you got to try to figure out where your
weather balloons are launched from because this whole
video pretty much applies to radiosondes all across the world just maybe a little
bit different format. Alright so once you figured out where is being launched from
then you got to figure out where this balloon flight is gonna go now they
launch at 1100 UTC and 2300 UTC every day like clockwork there’s a couple of
other special times they might launch from but it’s pretty much 1100 and 2300 UTC. Alright so now we figured out where these things are launched from now we
got to figure out where it’s gonna go. In order to do that you’ve got to use a website called HABHUB. We’re gonna run a flight prediction. The same website we use to run our flight predictions. We’re gonna figure out where they’re gonna launch
from so you got to plug in the latitude the longitude for the upper air
observation station and then the flight parameters. Now, typically weather service
flights are gonna launch at 5 m/s. They generally burst around
31,000 meters – it’s a good starting point to use and the descent rate can really vary
pretty wildly. If the parachute works perfectly it’s about 3 m/s. It can frequently be 4 or 5 m/s I’ve even seen it come
down at 10 or 12 m/s so it’s gonna vary quite a bit but throw
in a range there and then you can figure out roughly where this thing is gonna
land. Alright so now we’ve identified the upper air station we’ve got a
prediction we know roughly where this balloon is gonna fly now we got to start
tracking it, all right so you can do this from home you probably get a pretty good
signal but if you want to try to track the entire flight from start to finish I
recommend trying to get up somewhere high like this where you don’t have
nearly as many hills or trees or other obstructions that might be in the way of
obtaining a clear line of sight to the balloon flight and once you’re in a
pretty good spot you’re gonna need a little bit of equipment to do the
tracking. The first thing you’re gonna need is an antenna like this one here. This is
a parabolic directional antenna – very high gain so it’s gonna get really good
reception but it’s got to be pointed directly at the weather balloon the
entire time. Now, if you’re good with antenna theory you can save yourself a
lot of money you can build your own antenna that’s tuned exactly to that
frequency. For me, this antenna here is a 1700 MHz antenna. It’s
not perfectly tuned, but it’s close enough for my purposes. Now, the signal
from the radiosonde is not super strong so make sure you pay attention when
you’re buying things like cables and stuff like that. Either get some really
short cables or spend a little bit of extra money to get some low loss cables
so that you actually get a decent signal when you’re trying to
receive this. The next thing you’re gonna need when trying to receive this is a
filter and an amplifier. Now, we use this SAWbird+ here for the United States
flights because it’s perfect for this particular frequency it will
amplify the signals that we need and weed out all the noise that we don’t
want. Alright now that we got the signal filtered and amplified now we need to
pipe it into your computer in order to do that you need an SDR – that’s a
software-defined radio – looks like something like this. There’s a whole
bunch of different ones out there that you can get this one in particular this
is called a Bias Tee SDR. Bias Tee essentially means that it will power our
filter and our amplifier without needing external power. If you don’t have a bias
tee SDR you’re going to need to provide external power to that filter and that
amplifier. Now the SDR is gonna go into some SDR software on your computer
there’s a bunch of different versions that you can use pretty much any of them
will work just fine. I like to use either SDR# or HDSDR. HDSDR lately has
been the more successful one for me although I generally prefer SDR#
with pretty much everything else that I do. So in HDSDR you’re gonna make sure
you set this up as an FM signal. You’re gonna need to widen that bandwidth up to
make sure you can get the entire signal because it’s a pretty wide bandwidth
that these radiosondes are using. Alright now here’s the tricky part you’re gonna
take the audio from the SDR software and you have to send it to another software
program. To do that we’re gonna use a Virtual Audio Cable. It takes the audio from
one software program and brings it into another software program. That other
software program, there’s two of them you can use and I actually use both of them
at the same time. There’s one called Sonde Monitor and there’s one called Sonde.
Both of them will decode the radiosonde flights here in the United States. You
can also use something on GitHub for like a Raspberry Pi called radiosonde_auto_rx
It’s a great program, it just doesn’t have the support for the
National Weather Service flights here in the United States yet, but especially if
you’re worldwide it works great for radiosonde flights in other locations.
Now when setting up Sonde or Sonde Monitor, You have to make sure that your input source is the virtual audio cable. Once you’ve got that set up you can start your
tracking. In Sonde Monitor, all you really have to do is just select the type of
radiosonde and it’ll pick it up and start decoding it. For the other Sonde
program you gotta set a couple of parameters.
Here in the United States it’s an LMS-6 radiosonde however – tricky – in Sonde
you’re NOT gonna set this as an LMS-6 radiosonde, because the LMS-6 radiosonde here in the United States uses the “Mark II A” telemetry format. It’s confusing, but that’s the way it is. So you’re actually
gonna select the “Mark II A” telemetry format in the Sonde program. You also
want to make sure you select the Edge demodulator, you’ll want to do auto
threshold and invert the polarity signal on this radiosonde. That should
allow you to decode the LMS-6 radiosonde here in the United States. Now,
if you’re outside the United States you might have to play with these settings a
little bit to figure out what your radiosondes are using. Now you also want to make sure
in the Sonde program to plug in your own latitude, longitude and altitude and
that’s gonna help you figure out which direction you should point this giant
antenna in order to be pointing it directly at the balloon. During flight
the Sonde software is gonna give you an azimuth and elevation. That’s basically
where you’re gonna point this antenna to. So while the balloon’s in the air you’re
gonna want to look at the azimuth that’s being reported by Sonde and get
yourself a compass. That’s the direction – the compass direction – that you’re gonna
point the antenna in. You’re also gonna look at elevation and that’s the angle
upwards into the sky that you’re gonna point the antenna so those two
parameters are super important to make sure that your antenna is pointed
directly at the balloon during flight. Now your radiosonde signal at least here
in the US should sound something like this that’ll come and go depending on how
high it is in the sky or how far away it is but generally if
it’s really high up in the sky you should get a pretty strong signal even
if it’s 50 or a 100 or even 150 kilometers away. As it gets lower in the
sky your range is gonna get shorter and shorter as to how far you can pick it up
and that’s also gonna depend on how high up you are you can get to a really high
place to track these you’ll have a better chance of picking it up all the
way to the ground or all the way from the ground. At this point it’s time to
just hang out and track the balloon. Follow it along, watch the map, see where
it goes. Watch the altitude and see how high this
thing can get and then once it breaks now the fun part starts now you track it, follow it all the way down to the ground and see if you can figure out
where this thing lands. Now I’ve had the most success with just hanging out in
one spot. If you have an omnidirectional antenna you can throw it up on top of
your car or something and follow along with it and try to get close to the
actual landing spot. I like to just sit in one spot like this. I set up my
directional antenna, I sit in one spot way up high, follow the flight the whole
time, wait until I lose signal and then I go on the hunt. Now once you lose signal
from your radiosonde it’ll usually be either a couple of hundred maybe even a
couple of thousand feet off the ground so now you got to get close to it to see
if you can find this thing. So you’re gonna throw the antenna in your trunk
get it back in your car and get on the chase. Head down and get as close to the
last known signal as you can, maybe even try to translate that signal and figure
out where it might have come down. Get to that location get your antenna back out
and start pointing it where you think it might be. That’s where you’ve got to try to
use the directional feature of that directional antenna and you can try to track
down where this flight is. Once you can pick up a final signal and get a final
location then you’re gonna be on the hunt to try to get it, hopefully it’s
somewhere close by. If you get stuck up in a tree, that’s the nice thing about
these radiosonde flights there’s another one tomorrow. Alright so once balloon
lands then the fun part begins or the hard part begins I don’t know which
whichever one you want to look at it, but basically this thing can land anywhere. It
can land in the woods, it could land in the middle of a field and so today we’re
hunting one down that landed kind of in a little bit of both I have no idea what
we’re gonna find. Right now we’re walking through some fields here with super tall
grass trying to make my way through and it’s gonna hopefully be on the other
side of these trees here and we’ll see if we’ll see if it’s
stuck up in a tall tree or if we’re gonna be able to get this thing. I have no idea
what to expect, but it’s over that way and we’ll see what we find.
So the bad news about tracking weather balloon flights is you never know where
they’re gonna land but typically once you get to the area and you get that
final position you’re gonna know where it is and how accessible it’s going to
be and then once you really get close that first thing you’re usually gonna see is
that orange parachute and for today’s weather balloon there it is
we’re gonna go pick it up now. Alright that’s it. That’s how you recover a
National Weather Service radiosonde, follow a balloon flight, figure out where
it is and then, you know, as far as trudging through the woods and the fields,
you’re on your own for that I can’t help you with that, but that’s it. It may take
you maybe a day or two if it’s in a tough location, you can always come back,
they’re not going anywhere usually but maybe if find one, it’s pretty cool.
You can show it around, show your friends send it back so they can be refurbished
and sent up again and that’s it. That’s how you do it. Alright, yeah, make sure you
subscribe to our YouTube channel because we do this all the time. Sometimes we do
it live, sometimes we do it after the fact like this – ah! yikes! That one just
scratched me, but they’re – they’re a fun adventure here, right?! Going through the
woods, seeing what kind of stuff you can experience. Watching Tory get stabbed by
pricker bushes and try to get through the trees. This is cool. This is fun stuff.
This is science!! ahhh!! We do our own weather balloon flights too where we go through
the woods and recover ours. Usually that’s a little more exciting because we’ve
got cameras and stuff on board. There’s no cameras on these. These are just purely
scientific weather data… so… that’s it Alright, I’ve got to try to figure out where
the car is. I don’t where it parked. I think it’s that way.
I hope so. Alright, thanks guys. This was fun.
My name’s Tory, this is Overlook Horizon! Oh! Gosh! Hopefully I get out of here
successfully. Make sure you like the video subscribe to the channel so this
is not all for nothing, plus it’s some fun science stuff.
Alright, we’ll see you guys all next time. Goodbye.