I watching a wildlife programme on TV the other day which had a feature about urban foxes. The naturalists had fitted radio collars to some of the foxes and were able to track them over a wide area.One fox went off on a trek that lasted a couple of weeks and covered a distance of several kilometres.
In another programme radios have been attached to larger birds such as geese and ospreys to track their migration paths.
I wonder what frequency is used? One of the maturalists in the urban fox project seemed to be trying to DF a fox using what looked auspiciouslylike a 3 element 2m Yagi. I’ve seen similar antennas used o locate larger animals in Africa.
I would love to know what technology they use. My Kenwood TH-D7E APRS radio – despite being too big to use as a tracker for anythimg much smaller than an elephant – can run for only a few hours with the GPS enbled and the power set to a sufficient level to enable tracking over a reasonable distance.using a less than optimal transmitting ntenna.
I did a quick Google search and see that a couple companies use 100 to 108 MHz.
The Argos satellite tracking system is another interesting tool for tracking wildlife anywhere in the world. These wildlife satellite transmitters use 401.65 MHz.
Each time the satellite passes overhead it calculates the position of the bird (or whale, or whatever) by computing the doppler shift of the transmitter frequency. Location determination requires that four of these transmissions be received during a pass overhead. Easier said than done — the whale doesn’t always cooperate by staying above the water!
The accuracy is to within 150 meters. Pretty amazing, really, for a tiny omnidirectional transmitter often mounted to a bird’s back with a little battery that can last a year or two.
We used collars for Caribou herds here in Alaska for years, via satellite. With the polar ice melt, Polar bears (Now endangered species) have to hunt on land as seals don’t have the ice pockets to hunker down in. Bears tracked the same way. Makes villages up north a bit nervous. Even built a system to count Graylings traversing culverts to get upstream.
For fires. we also use lightning detectors to triangulate lightning strikes and satellite for RAWS system, Remote Access Weather Systems. Just an tracking FYI from the Tropical Alaskan Interior. HI