Looking for telemetry system for high altitude rocket

[TheLastBilly]

I just join my university's rocketry club, and my first task is to find a telemetry system for our next rocket. Our goal is to reach the 100 km mark, and constantly receive information from the sensors within the rocket during the flight. As you might realized, I'm no expert when it comes to telemetry or rocketry in general, but I do have some experience with electronics and ham-radio (I'll be applying for my Basic license in a couple weeks).

The club previously tried to use an RFD 900+ as a link between base and the rocket, but it failed during testing. Also, I've found telemetry links like the TeleMega, the MT-200, and the AIM-XTRA, not sure if they can be used like a RFD thought.

Do you know any transceivers that we can use for this particular project? Also, please let me know if I need to supply any more information (I imagine I do).

 

[mikec]

For this kind of range I'd go with the Digi XBee-PRO SX -- range of 105 km dipole-to-dipole, you'll probably need a higher-gain antenna on the ground.

 

[TheLastBilly]

For this kind of range I'd go with the Digi XBee-PRO SX -- range of 105 km dipole-to-dipole, you'll probably need a higher-gain antenna on the ground.

I just suggested that one to the group, and looks like they have have had bad experiences with xbee modules in the past, and are also ruled out. But do you know any instances in which that module was used? Maybe I could you them to the group leader to see what he thinks

 

[mikec]

I use the Xbee Pro XSC in rockets all the time with good results, but you have an irrational reason to not use them, whatever.

I don't know of any commercial rocket telemetry systems that have enough range.

 

[mdnehez]

The Lit on these guys says range in excess of 300,000 ft. I've seen them used pretty high, not 100 km though, might talk to them.
https://www.multitronix.com/

 

[DaveW6DPS]

What is your weight budget?

How much volume is available to electronics?

What antenna design are you looking at?

What telemetry data are you looking for?

What country/ITU region are you in?

It is probably unrealistic to expect non-licensed maker gear, ISM etc., to be reliable on a 100kM AGL flight. Multitronix does have a system that that they claim will work to 100,000 KM under optimal conditions. Of course optimal conditions are rare on real-world flights.

Depending on your answers to the questions above, there may be a number of options.

 

[FMarvinS]

If you have a ham license, look at:1. BigRedBee (BRB)- GPS 2watt transmitter; also 2. Check Byonics-they offer a 10 watt 2 meter transmitter for GPS tracking. Byonics and BRB have both successfully been used in balloon launches greater than 100,000 feet. Also Iridium Satellite Tracking may be your best bet (see https://www.rock7mobile.com/case-study-hab). In addition, the Byonics and BRB units utilize APRS transmissions, so a ham hand transceiver (e.g. Kenwood TH-D72A) would be needed to interpret the rocket transmitted GPS/altitude coordinates.

Fred, L2
ICBM, Camden, S.C.
KG4YGP

 

[ksaves2]

Ditto on Fred's response but you need to take into consideration of space, weight and whether or not your electronics play well together. Rf can dork deployment devices but the newer ones are resistant. 10 watts is going to take a lot of battery. Multitronix had a ground test to 300,000 feet and was still going strong. I would have more than one tracking device on a project of that caliber. Ham APRS only has the potential of one packet every 5 seconds. Kurt

 

[Worsaer]

With extreme altitude projects some electronic components may not behave as expected, and in some cases, can experience irreversible cumulative damage. You may want to do some reading on the effects of high altitude on different types of electronic components.

 

[jderimig]

With extreme altitude projects some electronic components may not behave as expected, and in some cases, can experience irreversible cumulative damage. You may want to do some reading on the effects of high altitude on different types of electronic components.

| This.

Although the hazard is low it is significant. You need vacuum rated components. The semi-conductors should be oven-baked dry (and kept dry) if you want to dot all your i's and cross all your t's.

If your team doesn't like XBee then consider the Murata DNT series of radios.

If you prefer a turn-key solution talk to James at Real Flight Systems.

 

[ksaves2]

Sheesh John, I freak'in forgot about RealFlight. Certainly would be turnkey if that's what the OP needs. No diddling and that helical GPS antenna is dastardly with working within an airframe or nosecone. Sarantel was bought out and I hear it's hard to get those antennas. Some of them had amplifiers. Kurt

 

[TheLastBilly]

The Lit on these guys says range in excess of 300,000 ft. I've seen them used pretty high, not 100 km though, might talk to them.
https://www.multitronix.com/

I'll be looking into that one, thanks! One of the members of our group is a ham radio operator, so I'll ask him what he thinks about that trasmitter.

 

[H_Rocket]

If you want to take another "full throttle" approach consider the BlackMagic solution. I would love to have a full stack of their UFC-3 system. However I also like eating and living indoors.

https://www.blackmagicmissileworks.com/

Make sure you are sitting down when you look at the pricing.

 

[UhClem]

I would be highly sceptical of any range figures. The usual standard for a telemetry RF link analysis (transmit power, antenna gains, polarization loss, receiver signal strength) is to maintain at least 15dB of margin throughout the flight. I doubt if those maximum ranges include that margin.

If you want to learn a little about how it is done by pros, read some of the documents from the Range Commanders Council. IRIG 106 would be a good place to start.

 

[plugger]

Hi OP,

I thought I should chime in and remind you that over 50km most COTS GPS chipsets (including uBlox) are configured in the firmware to report "no fix" despite having a continuous GPS lock. Curt von Delius's Phoenix 4 two stage stack was a concrete example of this.

Relevant uBlox forum link.
https://portal.u-blox.com/s/questio...valid-gps-fix-including-altitude-above-50000m

 

[jderimig]

There are reports that certain Ublox6 chipsets will report altitude above 50km. This was based on a simulated GPS signal from an SDR. I personally have not seen the data but this has been claimed.

 

[plugger]

There are reports that certain Ublox6 chipsets will report altitude above 50km. This was based on a simulated GPS signal from an SDR. I personally have not seen the data but this has been claimed.

I wasn't aware of that John but until someone is able to prove that in an actual flight I'd take it with a grain of salt. It's one thing to bench test but I prefer real world use cases personally.

 

[jderimig]

I wasn't aware of that John but until someone is able to prove that in an actual flight I'd take it with a grain of salt. It's one thing to bench test but I prefer real world use cases personally.

I agree.