Learned a lot in a short window. Thanks! I assuming you have to know the frequency values ahead of time. No searching active frequencies in the feel. Like scanning on a fm/am radio haha
What is the range on that, as in, when you point it in a specific direction, how can you tell if it's only a few hundred yards away, as against a mile or two? The signal strength,, or do they have a very limited range? Also, why not just use GPS, or is that limited because it only sends out signals periodically, not in real time?
Range depends on several things like power of transmitter, dynamic range of receiver, antenna, habitat of animal species (burrow or tree etc), weather to name some. So you can figure it out by testing transmitters with taking account most important factors mentioned before or homing animal couple of times and then remember gain values. If the animal is burrowing then the signal may not reach farther than 200 m while out of burrow signal may reach up to 1,5 km. Thick forest may reflect signals so you may start going to wrong direction. Reed may polarize signal so you have to twist antenna from vertical to horisontal position to hear anything. So it's tricky sometimes to estimate the distance. GPS is evolving better and better but there are limitations like small animal 1kg can't carry very big tag, up to 20 g. So you have several tradeoffs, how many locations you have per day, how many days tag battery works. Also in some conditions GPS works extremely badly like in dense forest so you might get bias where most of the locations are from open areas...List goes on. Usually GPS tags have VHF tracking also included because you need to get tags back somehow when tracking is finished and it adds weight to tags. In big areas and in bigger projects there is reasonable to use drone tracking. It's quite pricy on the other hand 40000$ per system. If animals are known to stay in certain area then maybe option is to use VHF data logging stations.
This receiver is out of production but similar thing from Telonics TR-8 costs 1500$+antenna 150$. But most of the cost of tracking comes from human labor.
Thank you for this. I got to try telemetry today for the first time!
Nice rundown, thanks.
really useful, thanks!
Learned a lot in a short window. Thanks! I assuming you have to know the frequency values ahead of time. No searching active frequencies in the feel. Like scanning on a fm/am radio haha
What is the range on that, as in, when you point it in a specific direction, how can you tell if it's only a few hundred yards away, as against a mile or two? The signal strength,, or do they have a very limited range? Also, why not just use GPS, or is that limited because it only sends out signals periodically, not in real time?
Range depends on several things like power of transmitter, dynamic range of receiver, antenna, habitat of animal species (burrow or tree etc), weather to name some. So you can figure it out by testing transmitters with taking account most important factors mentioned before or homing animal couple of times and then remember gain values. If the animal is burrowing then the signal may not reach farther than 200 m while out of burrow signal may reach up to 1,5 km. Thick forest may reflect signals so you may start going to wrong direction. Reed may polarize signal so you have to twist antenna from vertical to horisontal position to hear anything. So it's tricky sometimes to estimate the distance.
GPS is evolving better and better but there are limitations like small animal 1kg can't carry very big tag, up to 20 g. So you have several tradeoffs, how many locations you have per day, how many days tag battery works. Also in some conditions GPS works extremely badly like in dense forest so you might get bias where most of the locations are from open areas...List goes on. Usually GPS tags have VHF tracking also included because you need to get tags back somehow when tracking is finished and it adds weight to tags.
In big areas and in bigger projects there is reasonable to use drone tracking. It's quite pricy on the other hand 40000$ per system.
If animals are known to stay in certain area then maybe option is to use VHF data logging stations.
Interesting
Hi
Price. ...?
This receiver is out of production but similar thing from Telonics TR-8 costs 1500$+antenna 150$. But most of the cost of tracking comes from human labor.