Author Topic: How are radio frequencies managed at larger events?  (Read 5243 times)

Offline David Carter

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How are radio frequencies managed at larger events?
« on: March 04, 2016, 04:49:31 PM »
Hello all!

Many trackers are radio based, some in the HAM bands and some elsewhere. They typically have the option of selecting a channel so as not to interfere with other users or signals. Having never been to an LDRS or URRF, my question is how are these managed? Are the flyers responsible for just asking around (which I did at one of the regular launches), or is there an attempt to coordinate somehow?

I ask this because I've been toying with the idea of writing some frequency management software that would allow flyers to reserve a channel for a set amount of time to avoid conflicts. Is this a project worth doing? Would it be used if available?
David Carter
NAR 98850, Level 3

90% of rocketry is sanding!

Offline RKeller

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Re: How are radio frequencies managed at larger events?
« Reply #1 on: March 04, 2016, 05:56:25 PM »
at LDRS we had a big paper board that people would write down the frequency they were using. this was located at the RSO table so when you were getting your rocket checked you could make sure the frequency was available and write it down. you also had to go back and strike through your name/frequency once recovered. crude but it seemed to work pretty well.
Riley Keller
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Offline dbmccann

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Re: How are radio frequencies managed at larger events?
« Reply #2 on: March 04, 2016, 07:44:00 PM »
Not sure how you'd plan to use the software, but I see a couple complications if it was a scheduled out style thing-

-many projects people ballpark a time they want to fly, but may wait out the wind/light/clouds etc.
-prepping to hit a certain launch time is added stress, and prep time can vary from flight to flight
-lines/ call-in windows would play havoc on a schedule

the other issues would be recovery...  If you've got a frequency blocked out all day counting on a tracker being turned off at 2pm,  and the guy hangs in it a tree...you could be out of that freq until the battery dies.


Cool idea, and I've toyed with the same type of idea with flight card software,  but  pen and paper is fast and flexible.

Offline RKeller

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Re: How are radio frequencies managed at larger events?
« Reply #3 on: March 04, 2016, 08:13:36 PM »
what also may be helpful would be if there was a club database so people could make sure they at least choose a frequency that isn't already in use by club members. could just be a sticky in this forum...
Riley Keller
URRG
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L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline David Carter

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Re: How are radio frequencies managed at larger events?
« Reply #4 on: March 04, 2016, 08:15:07 PM »
The way I saw this working is reserving when you're ready to start prepping and releasing when recovered, not so much a reserve in advance.

Some trackers, are also flight computers or perform other functions. They need to be turned on and tested, and maybe acquire an initial GPS lock in the prep area like much of the rest of the onboard systems. A device activated during prep could interfere as easily as one on the pad or in flight. Even with a paper based system this would need to be considered. This might also mean people won't always get their first choice of frequencies.

What would make this system easier than paper would be entering the manufacturer, model, and channel rather than frequency which in the past people I've asked haven't necessarily known. It could map out any potential conflicts with anything already active. Of course you'd also have the option of entering the frequency for unknown or home grown devices.

There would always be operational challenges, and this would not remove the need for coordination by the launch folks.
David Carter
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90% of rocketry is sanding!

Offline David Carter

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Re: How are radio frequencies managed at larger events?
« Reply #5 on: March 04, 2016, 08:16:36 PM »
what also may be helpful would be if there was a club database so people could make sure they at least choose a frequency that isn't already in use by club members. could just be a sticky in this forum...

While this might work for smaller launches, it would be problematic if you have a large number of trackers. How many are typically active aat a URRF or LDRS type event?
David Carter
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90% of rocketry is sanding!

Offline RKeller

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Re: How are radio frequencies managed at larger events?
« Reply #6 on: March 04, 2016, 08:19:46 PM »
what also may be helpful would be if there was a club database so people could make sure they at least choose a frequency that isn't already in use by club members. could just be a sticky in this forum...

While this might work for smaller launches, it would be problematic if you have a large number of trackers. How many are typically active aat a URRF or LDRS type event?

yes, I was thinking for our regular club launches. if someone is buying a new tracker they could at least look up what channels/frequencies are already in use in our club.
Riley Keller
URRG
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L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high

Offline David Carter

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Re: How are radio frequencies managed at larger events?
« Reply #7 on: March 04, 2016, 08:24:38 PM »
what also may be helpful would be if there was a club database so people could make sure they at least choose a frequency that isn't already in use by club members. could just be a sticky in this forum...

While this might work for smaller launches, it would be problematic if you have a large number of trackers. How many are typically active aat a URRF or LDRS type event?

yes, I was thinking for our regular club launches. if someone is buying a new tracker they could at least look up what channels/frequencies are already in use in our club.

Well, most are field programmable. A simple web based version of the reservation app would allow you to reserve before you hit the field for the regular launches. This would probably be better than a permanent reservation system.

Are there many users using single channel devices? These could probably be accommodated as well, if only to let users know who they need to coordinate with.
David Carter
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90% of rocketry is sanding!

Offline les

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Re: How are radio frequencies managed at larger events?
« Reply #8 on: March 06, 2016, 08:25:49 AM »
Not all are field programmable.  :-\
 I have one off the original eggfinder units that has a fixed frequency (FYI 913)

Offline Greg Young

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Re: How are radio frequencies managed at larger events?
« Reply #9 on: March 06, 2016, 10:22:22 AM »
I setup a database of tracker frequencies for MARS club members a few years back. We could easily do that for URRG. Most use 440Mhz ham frequencies.
When we ran LDRS we went with the white board concept, asking the fliers to indicate their frequency while at safety check, and once their launch was over and rocket recovered, to return to safety and clear the frequency for use by others.
We also made sure to remind the returning fliers to turn off the trackers ASAP, if not already done.
Although certainly far from a perfect system, it works similar to what RC fliers use at AMA events.
Greg

Offline Larry Weibert

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Re: How are radio frequencies managed at larger events?
« Reply #10 on: May 08, 2016, 08:36:40 AM »
Hi Greg that's great info. I never got a chance to fly most of the bigger events at URRG as I am usually working them and never got involved with the Freq monitoring thing. That is a great idea it would be nice to have for urrg as well.
MRSI,TRA,NAR,URRG

Offline Greg Young

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Re: How are radio frequencies managed at larger events?
« Reply #11 on: May 09, 2016, 12:04:58 PM »
Larry, I thought I sent a copy of the frequency database for 440 (ham) frequencies we used. I don't recall who I sent it to...
If folks don't have it, let me know, and I'll email/post it here.
Greg

Offline Bob Krech

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Re: How are radio frequencies managed at larger events?
« Reply #12 on: May 28, 2016, 10:03:40 PM »
For years, the AMA has required that every flying field have a frequency board with frequency pins.  All transmitters are impounded and/or turned off unless the flier has physical possession of the a frequency pin, and has left his AMA card in the pin's slot on the frequency board.  In the RC world, apparently it is bad form to keep the frequency pin longer than 20 minutes.

URRG could have a similar frequency board system.  The multi-pocketed board would have all the available band frequencies labeled on the board's card slots and each slot would have a card with the same frequency.  When a launcher want to use the frequency for his tracker, he would remove the frequency card and leave his TRA/NAR card in its place.   That way you know who controls the frequency or if the frequency is available.

Bob

Offline Greg Young

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Re: How are radio frequencies managed at larger events?
« Reply #13 on: June 01, 2016, 08:53:05 AM »
Last year at LDRS we used a white board with name, frequency and parking spot number, so we knew where to find the flier if needed.
Not as fancy as a board with slots that holds cards (which I think is a neat idea, as it is like AMA's) but it worked pretty well.
As far as I can recall only once or twice was there a conflict, and that was because one rocketeer was not aware his tracker was on while he was prepping his rocket.  ;)
Greg

Offline David Carter

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Re: How are radio frequencies managed at larger events?
« Reply #14 on: June 01, 2016, 10:16:28 AM »
Is there a whiteboard planned for URRF?
David Carter
NAR 98850, Level 3

90% of rocketry is sanding!