Live detections of VHF beeper tags?

Tagging
1

Anybody using SGs to monitor standard beeper tags in realtime?

I know we can modify the FUNcubes to listen for beeper tags easily enough, but I assume they only show up in the “Live Pulses” feed, along with any noise, etc…

My goal is to isolate a narrow VHF spectrum for a single tag and get a realtime measure of signal strength for that tag. There would be several tags on the landscape in the same frequency range that we’d cycle through…

There’s probably an easier way to do this that doesn’t involve an SG specifically, but I was curious if others had tried anything…

Thanks,
Adam

2

Hi Adam, check the radiotracking.eu website. I suppose Ralf is doing what you want ( no sensorgnome indeed)

Bart

3

But if you are using a Pi already; you have can easily change the setup by plugging in an other dongle.

4

Thanks to you both. I have been chatting with Ralf a bit.

I know I can set the dongles to track the frequencies well enough, and register the tags. I’m more interested in whether:

  1. users have actually registered and tracked beeper tags with Motus?
  2. If so, does the tag detection/tagfinder output look similar to that with nanotags? (e.g., runLength, signal strength, timestamp, etc.). Can someone provide an example?
  3. What’s the minimum tag spacing we can use and still reasonably distinguish beeper tags? 5 - 10 kHz?
  4. Would be crazy to track nanotags and beeper tags simultaneously in the same frequency range? Probably no more than 20 tags at a given time…

I’m trying to pair a longer term diel activity and migration departure timing aspect (traditional nanotags) with some local tracking (home ranges, nest location, etc.)

Appreciate any thoughts/experience!

Adam

5

Hi Adam,

1) users have actually registered and tracked beeper tags with Motus?

Not that I'm aware of. Some users have deployed them, but have been limited
to just getting raw pulse data from their own receivers.

2) If so, does the tag detection/tagfinder output look similar to that
with nanotags? (e.g., runLength, signal strength, timestamp, etc.). Can
someone provide an example?

The tag finder and motus server need some work to deal with beeper
tags. It's a long standing open issue; one pointer into that
is here:

  https://github.com/jbrzusto/motusServer/issues/153

I'm afraid I've failed to deliver on promises to implement it so far.

3) What's the minimum tag spacing we can use and still reasonably
distinguish beeper tags? 5 - 10 kHz?

You'd need to do some testing on tags to assess how much their output
frequency varies with temperature; the other source of aliasing is
variation in the funcube or rtlsdr local oscillator frequency; what
little I've looked at in data suggests funcubes are typically within
2 or 3 kHz of each other when at the same temperature.

4) Would be crazy to track nanotags and beeper tags simultaneously in
the same frequency range? Probably no more than 20 tags at a given
time...

The SG's onboard pulse detector, or at least the harness code,
would need a bit of work to allow detection of both the nanotag 2.5 ms
pulses and the typically 10-50 ms pulses from beeper tags.
A suitable deployment.txt can make this happen right now, but it might
not be efficient enough when running multiple funcubes on a (single-core)
beaglebone-SG. See https://sensorgnome.org/The_Web_Interface/Changing_what_the_SensorGnome_does_by_editing_the_Deployment_file/Syntax_of_Deployment_Files/Connectivity_Tags?highlight=beeper for an example.

6

Hi Adam,

Look out for beeps that join each other so you get a mess of beeps
that are not possible to distinguish anymore. We will do the same with
around 60 tags, and by that, with 3 frequencies of Nanotags it becomes
already mess... So; taking some different pulse intervals can help you
already a lot; but taking more frequencies in 1 MHz band helps you
much further I assume.

René

7

Thank you both.