10000 ft Rocket communication

[Saeed Johar]

Hi,

I am looking for communication modules for rocket, which would travel around 10000ft.
What type of antenna may I use along?

 

[John Kemker]

So, what kind of communication are you wanting? GPS info for tracking? Telemetry, such as temperature, air pressure, etc? A simple beacon? It really depends on the specific application.

 

[KilroySmith]

And perhaps what country are you in? Different countries have different laws about what you can/can't use.
Lots of people here to help if we have enough information.

 

[Saeed Johar]

Thanks for your responses.

I need real-time flight information which includes the data from the pressure sensor, accelerometer, and GPS data(for recovery) after deployment.

Is this detail enough for you?

 

[Voyager1]

There are several options that might depend on what country you are in and the RF licensing regulations. You generally have a choice of 430 MHz band or 900 MHz bands. Depending on the actual frequency you might require a license to use the unit where you are. Some places to start are:

https://eggtimerrocketry.com/home/eggfinder-gps-tracking-system/
https://www.featherweightaltimeters.com/featherweight-gps-tracker.html
https://www.missileworks.com/store/#!/GPS-Tracker-Systems/c/19848147/offset=0&sort=normal
https://www.multitronix.com/
https://altusmetrum.org/index.html
https://entacore.com/electronics/aimxtra

Some of these support extra telemetry such as accelerometer and temperature data, as well as GPS.

 

[Saeed Johar]

I was aware of cc1101 with a range extender cc1190 operating at 868MHz.
I was looking for alternatives.

How will aluminum body affect the communication?

 

[Voyager1]

I was aware of cc1101 with a range extender cc1190 operating at 868MHz.
I was looking for alternatives.

How will aluminum body affect the communication?

If you install any RF device inside an Aluminium body it will shield it. Nothing in; nothing out! You would need to locate the antenna outside the Al body. If you install your GPS inside an Al body it will not receive the GPS signals and it won't be able to transmit the telemetry.

What is your nosecone made of? Many telemetry systems are located in a fiberglass (or some other RF transparent) nosecone.

The same applies to using Carbon fiber - it can significantly attenuate or block RF due to its conductivity, but this might depend on how it's layered.

 

[Saeed Johar]

I can use a patch antenna, which will be attached to the rocket body.
My ground station will be using Yagi. Is it going to be a right choice?

 

[Voyager1]

A patch antenna will probably restrict you to the 900 MHz band. You might need one on each side of the rocket body depending on its configuration to optimise the radiation patten. At 430 MHz a patch would probably be a little large.

A cross-polarised Yagi would probably be a good receive antenna.

 

[KilroySmith]

Aluminum bodies are uncommon in model rocketry, in my limited experience. Something about making them look too much like real-life missiles. Are you doing this project in the USA?

 

[Saeed Johar]

A patch antenna will probably restrict you to the 900 MHz band. You might need one on each side of the rocket body depending on its configuration to optimise the radiation patten. At 430 MHz a patch would probably be a little large.

A cross-polarised Yagi would probably be a good receive antenna.

We will most probably be going with 433MHz.

 

[Saeed Johar]

Aluminum bodies are uncommon in model rocketry, in my limited experience. Something about making them look too much like real-life missiles. Are you doing this project in the USA?

We are looking for something inexpensive and light. The project will be in Turkey.

 

[KilroySmith]

Inexpensive Aluminum? Go talk with a Hang Glider pilot - they'll likely either have an old glider, or old glider parts, that they might be willing to give you. I'd be happy to use the 50 or 60mm 7075 thin-wall tubing from the leading edges of my old glider as a slick rocket, but that's not gonna happen in the USA. There are also a lot of gliders with 50 or 60mm carbon fiber leading edges that would work also; once again, they're throwaways to the pilot when the glider is over 5-10 years old.

 

[Saeed Johar]

Inexpensive Aluminum? Go talk with a Hang Glider pilot - they'll likely either have an old glider, or old glider parts, that they might be willing to give you. I'd be happy to use the 50 or 60mm 7075 thin-wall tubing from the leading edges of my old glider as a slick rocket, but that's not gonna happen in the USA. There are also a lot of gliders with 50 or 60mm carbon fiber leading edges that would work also; once again, they're throwaways to the pilot when the glider is over 5-10 years old.

Since we're not in USA, things are different here.

Thanks anyways.

 

[cerving]

Turkey can use the license-free 868 MHz band, we ship Eggfinder transmitters on three different frequencies: 869.425, 869.525, and 869.625 MHz. That is the only range that allows license-free 100 mW output in the EU with a decent duty cycle (10%), the 900 MHz band is used by cellular phones over there so it's out. The other alternative would be the 433 MHz band, in order to use 100 mW somebody on your team would have to be a licensed Ham radio operator. Be aware that putting a patch antenna on the outside of the rocket means that it's only going to be able to be received by the receiver if that side is pointing towards you; the back and side wave propagation from a patch antenna is very weak.

 

[Voyager1]

We will most probably be going with 433MHz.

There are patch antennas available for 433 MHz, e.g., https://www.amazon.com/Beyondoor-Adhesive-Frequency-Performance-Straight/dp/B07PG7BGGM
You might need to use at least 3 of them to go around the airframe to provide a useful 360 degree radiation pattern.

You could design your own to suit the diameter of your rocket. Personally, I would prefer a monopole mounted in an RF transparent nosecone because of its simplicity.

Here is an interesting application https://vtenn.com/Blog/?p=195
And here is one that is available from IEEE if you have membership https://ieeexplore.ieee.org/document/7938446