Long Range GPS Tracking

[macking]

Hello,

I am new both on the forum and into rocketry so apologies if I make any mistakes!

I am working on developing the GPS recovery system for my rocketry club and have been considering two options

1) Developing my own tracking system & ground station
2) Buying out-of-the-box solutions

For the first option
1) I was wondering about anybody's experience with creating their own tracking system and setting up their own ground station & transmitting systems.
2) If they were able to create their own system on a non-licensed band. I have seen that some out-of-the-box solutions utilize non-licensed VHF/UHF bands but none for self-made tracking systems and was unsure why. The self-made systems I saw all used APRS protocol and that only operates on HAM bands, but surely a self-made system could be made to operate on a non-licensed Frequency band as well?

For the second option
1) What are peoples recommendations?

I've seen options from Featherweight, EggFinder, and Big Red Bee. But I am still a novice in this area and am unsure as to the pros and cons of each. We are thinking of buying a Featherweight Tracker, and just the tracker with no ground station, and making our own ground station. Of course, that means I'd have to figure out how to develop the ground station. (If anyone has any good resources on how to do so would be amazing to have them!!)

This leads me to my last question.

1) Do you have any resources (websites, books/journals) that you could link to help in this process?

I have a much larger preference for creating my own entire tracking system & ground station as its much cheaper. But I couldn't quite find good resources on how to create a system, so if anyone has any recommendations would be much appreciated!

 

[GrouchoDuke]

Developing your own is quite an undertaking. Reverse engineering someone else's protocol is an even bigger challenge. If cost is the driving factor, go the EggFinder route. Cris makes great solder-yourself kits and their range is quite good for many fliers (I saw him fly probably 6 miles away in Vegas without any issues).

Featherweight is currently the only LoRa transmitter designed for rocketry that I know of, although there are several others in development. LoRa range is quite spectacular for the power used with simple antennas.

That said, developing your own is really rewarding. It's definitely not for the faint of heart though.

 

[kswing]

I built my own tracking system using components I purchased from Adafruit. I had to do a bit of easy soldering and write a bit of code to get the pieces to work together. It uses the unlicensed 900MHz band, so, it should be good for a few miles line-of-sight. I've personally used it on a rocket that went to over 8000 feet and drifted about a mile. In my latest iteration it uses Bluetooth to send location information from the ground station to my Android tablet where you can use the GPS Rocket Locator app to map it. The app takes standard GPS strings as input, so, I basically send the tracking data from the GPS chip down from the rocket via 900MHz LoRA and then over to the application via Bluetooth.

If you decide to go this route let me know and I'll share my source code. Here's a link to the original build thread: https://www.rocketryforum.com/threads/arduino-altimeter-tracker-advice.137022/

 

[Hobie1dog]

to the forum

 

[Handeman]

Welcome.

MissleWorks also sells two 900MHz GPS tracking system. The T3 and the RTx/GPS System. I've been using the T3 with Rocket Locator on my Android phone for years now and it works great.

 

[Crayok]

Developing you own is going to be a bit of an undertaking but it is part of rocketry to build things! So if you enjoy electronics go for it. It may not be a quick solution, lots of time testing and coding. If you do, I highly suggest to use common protocols such as APRS (1200 baud) (format not frequency) this way most amateur radios have a chance to decode the packet (radios that are capable of say 900Mhz reception). LoRA changes the game a bit by using slower bit rates to gain distance. Lots to discover.

As to existing products there is quite a few to select from, all varying in price and complexity . lots of suggestion on RTF and above.

Some high level discussion, not technical.
https://www.rocketryforum.com/threads/i-have-a-dream-standardization-for-gps-trackers.169122/
Also for receiving maybe an SDR and software decoding
https://www.rocketryforum.com/threa...r-to-decode-aprs-packets.169027/#post-2199299
dB

 

[charrington]

If you are developing it for a competition or use in something expensive, I highly recommend flight testing it in a smaller more simple rocket with similar materials and max acceleration.

 

[bdureau]

I am currently testing a very simple GPS tracker using an Android device to see where the rocket is . I have published the code on my github
https://github.com/bdureau/SimpleModelTrackerIt is using long range Lora 1W 433 or 900Mhz telemetry module. I should receive some new PCB soon