#radio tracking

[manyrollingeyes]

[theprivatei]

Radio telemetry tracking, triangulation from two known points using an excel spreadsheet.

Recently we’ve been involved in an asset tracking project for a client.

The assets were small enough that a GSM/GPS device was likely to be too large to be able to be hidden effectively, when the necessary battery for long-term unattended use was included. As a result, we installed small radio beacons, designed for the tracking of small animals.

To locate the tracking beacons, we use either a yagi antenna with a receiver, or a car-mounted radio-direction-finding set-up with a series of aerials mounted to a vehicle in a plane.

Tracking multiple objects over a prolonged period of time, we end up with a large amount of data in a “position, bearing" format, or more precisely, “easting, northing, bearing".

I scoured the internet in vain looking for a spreadsheet which contained the formulas necessary to turn two position/bearings into a third position - namely the location of the tracked asset. The trigonometry is not especially difficult, but nowhere was a pre-configured excel spread sheet to be found!

Sitting down to build one, I feared it would be a difficult and time-consuming process (I’m not particularly mathematically inclined) but was pleasantly surprised to have it constructed and tested within the hour.

I expect it will be of assistance to other investigators, zoologists/ecologists etc who are tracking birds, mammals or other animals, people involved in vulnerable person tracking operations, and perhaps even to the amateur radio direction finding crowd.

I include it here, as an attachment, under a Creative Commons AU 3.0 licence.

To download the file, click HERE or right-click and choose save-as.

[alixs-adventures]

Radio telemetry (or radio tracking)

One of the activities that I regularly perform out on the reserve is radio tracking. In order to determine where the squirrels are, we collar the squirrels with radio collars. These collars have batteries in them and put out a signal that can be picked up by an antenna. We use an antenna and device to look for the squirrels. You can see me in the picture tracking a squirrel. I like to hold the receiver close to my ear so I can hear the beeps better. When you come in range of a squirrel with a collar, the device will beep. As you turn down the gain on the instrument, the signal becomes fainter (aka you have to move closer). As you point the antenna, the signal will beep louder or quieter, depending if you’re pointing it in the right direction or not. It’s almost like a treasure hunt to search for it, ending when you point the antenna at the ground (the burrow that the squirrel is in) and it beeps the loudest.

Radio tracking is a lot of fun, but it takes a lot of time and involves a lot of walking. There are daytime and nighttime tracking schedules where we look for approximately ten squirrels. It’s great until you can’t pick up a signal for a squirrel. For instance, sometimes squirrels will leave the reserve, which is fenced. If they’re a few hundred metres past the fence, we can’t get a signal for them and we wander around aimlessly for hours. Sunrise, one of our squirrels, is nowhere to be found. I’ve searched for him for about eight hours now and I’ve never picked up a signal for him. It’s frustrating as heck sometimes, but we can usually find them.

My most interesting story about radiotracking was with Googly Eyes. I could not get his signal in the morning anywhere, so I went back out in the afternoon and searched again. That time, I heard beeping so I walked out to it. It led me to the centre of a field, nowhere near any burrows. I was confused, so I searched around until I found what I was looking for…. Sort of. I found the collar…and what remained of the squirrel…in poop. Yep, Googly Eyes is no more. We didn’t have a large enough fecal sample to identify what ate him, but we could deduce that it was a mammal. Squirrels have natural predators here, like jackals and small cats. Unfortunately, these things happen. It is nature and the circle of life. I thought it was cool though. The collar worked, even after being digested!

Anyways, now you know about radio tracking! We track the male squirrels in order to determine homerange estimates (how far they go, where they live) and to see if they change when we manipulate the hormones of the squirrel. Pregnant female squirrels are also collared in order to find their isolation burrows, where they have their babies. Dylan sets up trail cameras to see what comes in and out of those burrows, because baby squirrels have a high mortality rate and we don’t know why. That’s all for now! I’ll tell you guys about handling the squirrels some other time, as well as observations!

Toodle pip!

[enchantinglittlestories-blog]

i now have some experience in radio tracking! its actually harder than it looks especially when you are in a built up area! but it was fun and will look AMAZING on my cv!