High Altitude Balloon Communication

Projects Discussion and Showcase Science and Measurement
1

I'm trying to create a High Altitude Balloon (HAB), and the main problem I have is communication with it. I have a couple of LoRa RFM9X Radios which can apparently do 20Km Range. Many sites suggest using LoRa radios to communicate with the balloon, but my issue is, I thought the maximum range for LoRa Radios was around 20Km. Is this different in the air as oppose to on the ground?
Can I increase this range in any way to maximise my range?

Does anyone have any other simple but cheap methods of communication with the balloon?

Thanks

2

My own attempts with LoRa were pretty disappointing, so I went back to RFM69. I'm no expert, but this site might have some useful information for you.

3

The difference is entirely in your antennas. Every antenna has a radiation pattern. They need to have maximum gain in the desired direction, not spread around the entire universe.
Do you have options available for different antennas?
Paul

4

I currently have screw on antennas, which I'm sure I could replace with alternatives.

5

I think I also have a TV satellite dish, which I could use at the ground station to amplify the signal?

6

Does it have an LNA and down-conversion to match your unknown transmitter/receiver?
Paul

7

I thought the maximum range for LoRa Radios was around 20Km

The current record for LoRa transmissions from a balloon is somewhere around 800 km. You do need an antenna on both TX and RX, and unobstructed line of sight.

I currently have screw on antennas

Are they specified for the frequency in use? Post links to everything, so we don't have to guess. A satellite dish will not be useful.

8

I have 2 of these rfm9x radios.
The antennae I have for them are not optimised for 433MHz, they are taken off a WiFi Router.
Will the RFM9X's be suitable for further than 20km radio transmission to each other, not to a LoRaWAN tower, if I were to use these antennas?
Ideally I'd be able to communicate between my station and the balloon over more like 50km.

9

Hi, @benbenson2004
Welcome to the forum.

This link should help you, it even includes a High Altitude tracking software.
This is a well documented site by one of forum members' , I believe.

Tom... :smiley: :+1: :coffee: :australia:

10

That's probably an optimistic ground path distance (obstacles completely dominate the actual range possible).

However paths from ground to a balloon are guaranteed line-of-sight, so you should easily get much more range than a ground path(*). However sometimes the protocol in use enforces range limits by timeouts - 20km round-trip takes 133µs for instance.

(*) https://en.wikipedia.org/wiki/Free-space_path_loss#Free-space_path_loss_formula

11

Impossible to say. Using the wrong antenna will REDUCE the range and can even damage the transmitter.

I suggest to follow the suggestions on the Adafruit page, but a 1/4 wave (17 cm) piece of wire is always pretty good for 433 MHz.

12

Hello
Go and ask for support from your local radio amateur section for the design of a 70cm full size arial.

13

20km, you must be kidding.

Way back in early 2015 a record was set for two way control of a high altitude balloon, a humble foil party balloon in this case, 269km @ 434Mhz @ 10mW;

That was using fairly modest 1042bps LoRa and at a low altitude of 8km, at lower data rates you would get 3 times the distance.

January2015_10
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1 Like
14

832km, 868Mhz, 25mW;

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