FlightAware Discussions

Tethered balloon site

I’m a newbie to this forum. I recently started running a PiAware rig and it does well in terms of craft/positions counted. But there are “holes” in the coverage due to local topology - there are steep hills nearby.

So I began thinking about a tethered balloon to raise the PiAware rig ~100 meters, say. (About the limit for E’net over Cat-5. :slight_smile: I searched the forum for balloons but didn’t find anything that addressed my interest. I did find some nice pix of the Albuquerque balloon fest.

Has anyone deployed a PiAware under a tethered balloon?
Has anyone opened a discussion topic about it that I should go read?
Is there a good reason not to try it?

Looking for whatever input I can find on this topic at the moment. Thanks.

Well, that is a let’s say novel idea, although there are people known to have used a crossbow to shoot an antenna cable up in a tree. :wink:

There is a hobby called High altitude balloons, they do something different but maybe there is some inspiration or carry-over.

http://www.randomengineering.co.uk/Random_Aerospace/Welcome.html

You could also use heywhatsthat.com to see your current limitations and how it would be affected by being higher from the ground. Maybe it it is not worth the trouble.

The list of difficulties is probably rather long. How to power it, does POE work in such distances, are there government regulations not allowing it, HOA, other family members, extrem weather, storm, heat in the summer, cost of a balloon carrying the payload, maintenance of a balloon, do balloons even exist who stay in the air for a prolonged time?

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There are certain people using tethered Balloons, not sure if they also receive ADS-B.
Pretty sure they are not feeding FlightAware though:

Definitely check how long of a tethered balloon / kite you are allowed to fly in your local jurisdiction.

I would probably go with WiFi and a lighter power cable.
Also i’m curious where you are located that no one would mind what you are proposing.

If there are that few people where you are, maybe a solar powered station on the next peak connected with some directional WiFi antennas might be easier to execute.

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  • I like the idea of the crossbow but don’t think it would solve my problem.
  • Thanks for the link to RandomEngineering
  • I’ve been to heywhatthat, which generated some very nice maps for me. They confirmed what I’d deduced from topo maps of my area: I’m up against a wall. There’s a hill 200 feet above me about 1/2 mile to my WSW - can’t see around it.
  • That’s a great list of questions too.

Appreciate the comments.

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The aerostat type is out of my price range, I’m sure. Those are mostly government jobs, right? But that’s the idea.

  • WiFi’s worth a try. I was worried about wind drift with it.
  • I’m on 7 acres in a subdivision that’s 60 years old. The HOA is basically for road maintenance.
  • Actually, there’s a road on that “next peak” and presumably people living there. Easiest thing would be to talk them into letting me site there. But directional WiFi might work too – I think I’d have good line-of-sight.

Thanks for the suggestions.

@biekerc: Balloons can be found that are fairly long-lived. They’re not like the explode-after-deployment latex weather balloons.

In fact, if you do a web search, there are any number of people using tethered balloons for advertising and for amusement rides. (Don’t know if I’d ride one of them.) Then there’s the military too, as @wiedehopf pointed out.

The problem is to find one scaled down to light instrument use. My guess is that the cable weight – tether, power and/or network – would be the biggest loads. The PiAware kit would probably be peanuts by comparison.

I guess even those might last a little longer if they stay at a lower altitude. And are probably cheaper and maybe a good starting point for a protoype.

Yes, maybe even the newest type of Pi zero might be powerful enough. Not sure how an antenna will be affected by the movement up in the air.

Yes, I have seen those, do they use helium? How often does one have to refill them, and how is that done, what does it cost?

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Right. Keeping the latex balloons near sea level prevents them from popping. And they’re cheap on Amazon or Alibaba. But I read that latex is easily torn (trees or strain at the tether). Also, I don’t know how latex responds to UV exposure.

Prototype is a good idea, tho.

Good suggestion.

I’ve read that they’re helium-filled. I don’t have answers to the other questions (yet).

In russian. Experiment with quadcopter. The maximum range obtained is 380 km.
http://forum.adsbradar.ru/f19/eksperiment-s-letaushim-setapom-orange-pi-dongl-kvadrokopter-2135/

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Thanks - interesting article.

I’d thought about trying this with my DJI drone. If I can come up with a “power plug” that lets me replace the drone’s battery with DC from the ground (via a tether) then I wouldn’t be worried about the 15-20 minute limit on battery-powered flight. (I wonder how long those quad rotors will run non-stop.)

The payload weight will be the big factor, I think. My DJI will only lift ~1 kilogram.

That’s an expensive endeavor and I contemplated it too. But the motors are not rated for 100% utilization time at full load, you would have to de-rate them (lower RPM’s). I was planning to send just two small speaker wires for sending the power up there for the motors and Pi, and connect the Pi back via WiFi. Added all the weights, the tethering wires (anchor it in three directions) and it was too much.

I can’t fly balloons or drones past the tree line, I am too close to the airport. You need to check with local regulations, fines can be hefty.

Eventually I “pulled” the antenna up a high tree in my yard. Wasn’t a crossbow (also illegal to discharge in my city limits), it was a slingshot with a fuse :smile:
I used it to send over the tree a fishing line, then pull with that a paracord with the antenna, amp and cable installed on a PVC conduit (tied at gravity center).
This is how it looks now, without leafs. I couldn’t shoot over the higher branches, there were too many leafs then.

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Thanks for the experimental report on your drone, @SoNic67.

Yeah, that was a concern. A few hundred feet of wire could end weighing a lot more than the battery and reducing the payload to 0. I was thinking of trying the drone as a prototype - just to confirm that the elevation change I’m shooting for would give the results I expected.

Thanks for the annotated pic. I’ll guess that puts your aerial 25-30 feet above grade? And you used a bottle rocket? (Cool.) The tree mount looks like the best approach for your situation. It’s a lot cheaper and easier than putting up a tower, right?

Putting aside the wild ideas about balloons & drones, that would be my best approach too. My aerial’s currently about 15 feet above grade. A tree might get me another 10 or 15 feet above that - or about what you appear to have in your tree.

My estimate, tho, is that the aerial needs to be 200 feet higher to clear the hills blocking the view to the SW and to the N. That’s based on what Heywhatsthat tells me and on looking at local topo maps.

But I don’t have any 200-foot tall trees, hence the wild ideas. :crazy_face:

Do you have access to a piece of land on those hills to place an antenna?
I would try a passive repeater.
Basically you would have those items:

  1. A vertical-polarized antenna capturing the ADS-B packets.
  2. Coax cable with or without amplifier.
  3. That vertical antenna is connected with a coax cable to a directional antenna (tuned to 1090MHz, it can be the variant in a can). This second, directional, antenna is oriented towards your place.
  4. At your place you install another identical directional antenna, to receive the signals from the hill. Might need an amplifier here too, especially if you don’t have one on the hill.

This was used in several locations as UHF TV repeater (active, one way mode, like you need for ADS-B), cell tower repeater (passive, bi-directional mode), WiFi repeater (passive, bi-directional mode).

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Apart from not having a permit to radiate on 1090MHz it’s just way easier and cheaper and get a directional WiFi connection going.

You could also buy yourself a 200 ft tower:
https://www.3starinc.com/rohn_45g_complete_200_foot_110_90_mph_guyed_tower_r-45g110r200.html

I guess getting permission to build a site on that hill is gonna be easier/cheaper :slight_smile:

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That’s why I was saying directional. If is passive, you don’t need permission. Heck, RF waves reflect all the time from… lets say buildings, metallic film treated windows or metallic objects like cars.
Especially with a good directive antenna like a wave guide that was discussed somewhere around here.

For WiFi you might be not be permitted to send a signal outdoors in any conditions.
https://www.air802.com/fcc-rules-and-regulations.html
And doing that would require much more local power than just the small in-line amp (to feed the whole Pi and receiver). Plus… those really would be temptations for thiefs, if not secured.

Looks like he has woods back there, so that might impede anyway the installation of the repeater, he would have to clear those trees for direct line of sight, like I did :slight_smile:
Not the exact location:
https://goo.gl/maps/txxKZSbRdLH2

I also saw people here in US building towers, you can buy them online and have a crew assemble/raise them locally. But those really require permissions and cost real $.

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I would be very very cautious about anything that could radiate on 1090MHz. That part of the spectrum is highly regulated.

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Dully noted, edited and took out any active repeator suggestions.

This has turned into an interesting discussion. I appreciate all the suggestions & comments, folks.

Right. The hills around here are heavily wooded (with short trees), so any kind of radio link (1090Mhz or 5GHz) between the Hill Site and my site would have its own set of problems - starting with a power supply.

That’d be the ticket for sure. But (a) I’m on a narrow ridge and don’t believe I’d have clearance for all the guys & anchors, (b) my HOA’s pretty easy but they might have something to say about a tower, and © I can buy a pretty decent motorcycle for 10 large.

Here’s a little background, for those interested. (Horizon maps from HeyWhatsThat.) Since I can see downtown St. Louis on a clear day (a little over 20 nm), I thought this would be a good site for running a PiAware.

a. Radio horizons at 10K and 40K feet for my current site.

Not seeing Chicago, KC, or the whole of southwest MO is definitely sub-optimal, tho. I found a local topo map to locate the high point blocking the view to the SW.

b. Radio horizons (10K / 40K) at the Hill Site. Now we’re talking (tho I’m a little surprised to lose Memphis).

It turns out there’s a road up that hill and Google Map’s satellite view shows three houses there. If one of those has an ISP and is open to a little co-location, then their ISP would solve the backhaul problem for me. Or maybe they’d be interested in running their own PiAware.

c. Just for grins, let’s put that aerial atop the Gateway Arch in St. Louis.

Oh, yeahI can see for miles.

My next step is to go knock on doors on that hill. If that doesn’t work, I’ll check the balloon route in more detail. I sent a query to the RandomEngineering folks (as @biekerc suggested) to see if they know who could outfit me with a tethered balloon for a light instrument package.

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For a while I used an older cell phone as hotspot for a remote Pi. At that time I had a free 1GB data plan (on FreedomPop LTE, AT&T based), but data from ADS-B can easily go trough that, especially if MLAT is enabled.

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Add a solar panel & battery and that would be a solution.

FreedomPop offers a hotspot box (no phone needed). I tried one of those a few years back since it was free on a trial basis. But the LTE coverage was poor where I am and so it didn’t work very well - intermittent connections and slow when it did connect. I didn’t continue after the trial.

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