Bandwidth The number of radio frequency units, e.g. between the lower and upper frequency limits a receiver can detect.
Battery life configuration The pulse rate and lengths set to optimise the trade-off between the distance the tag can be heard from and the time it lasts.
Biotelemetry Recording biological data from a distance.
Coded Tags VHF tags that send codes rather than simple beeps, allowing for more than 200 tags to share the same frequency. This means that all tags can be recorded at the same time reducing the chances of missing an event. However, manual tracking is less easy with coded tags.
Geolocators Tags capable of measuring and storing data on light levels, e.g. Sunrise and sunset. Once retrieved this data can be used to calculate the latitude and longitude using a process known as light-based Geolocation
GPS Argos The Argos system is a set of satellites that can relay location and sensor information from the GPS Argos device to your e-mail inbox without the need to retrieve the collar.
GPS GSM Global System for Mobile Communications (GSM) allows GPS locations to be sent via SMS message to a mobile phone or PC when the device is in a GSM coverage area.
GPS tracking Recording the location of an animal using the Global Positioning System.
GPS Tracking Collars use the global positioning system of satellites to determine the precise location of the animal. Locations are logged to the device and these can then be downloaded from the collar in various ways.
Micro-controlled tags Pulse characteristics are controlled by a tiny, single-chip computer (microcontroller) which gives flexibility for more sophisticated sensing and powering down of a tag when not needed.
PIT tags Passive Integrated Transponders that reflect back a unique number when interrogated using external energy. Typically used for pet identification.
Potting Protective layer around the transmitter and cell. Tags that might get chewed, or are likely to be submerged need heavy potting, whereas small birds need tags to be potted lightly, because they are unlikely to damage the tag and it is important to keep the weight down.
PTT Platform Transmitter Terminal, used for satellite tracking.
Radio tag Transmitter circuit, that may include a sensor, and a cell (battery) that provides the power, and it is then protected with potting and furnished to make attachment to the animals as easy and kind as possible.
Radio-telemetry Recording data (over and above the location) from a distance using a radio tag.
Radio-tracking Recording the location of an animal from a distance using a radio tag.
Remote Download GPS locations can be retrieved remotely from a tag, e.g. using GSM/Iridium phone networks, Argos satellites or UHF radio waves.
Satellite Tracking Signals from the tag are received by satellites and interpreted using the Doppler Principle to give a location. Good for migratory animals and global movements but low accuracy.
Store-on-board The GPS tag must be recovered and physically linked to a computer to download stored locations and other data.
Tag life The duration expected from a tag given the pulse characteristics and the capacity of a cell when under a pulsed load.
Tag range The distance from which you expect to hear the tag, but which is very environment dependent. The can also be known as detection range, or signal range.
Telemetry Recording information (over and above the location) from an animal at a distance.
Temperature Depth Recorders (TDR) These tags record ambient temperature and depth by water pressure, so can be used to tell you about the diving activities of seabirds.
Template Fit An advanced technique for estimating GEOLOCATION from light logs. It improves on threshold-based models by using a light curve that is less influenced by cloudiness, horizon details, atmospheric refraction and dust loading. For more information see the Template Fit paper.
Transmitter Small sealed units that contain the electronic circuitry needed to produce radio signals. To be built in to a radio tag, they must be fitted with a battery, antenna and mounting system. For more information, see the Radio Tags page.
UHF Ultra High Frequencies (> 300 MHz)
VHF Very High Frequencies (30 - 300 MHz)
Yagi Antenna Receiving antenna with a reflector element and one or more directors fixed in parallel on either side of a dipole antenna: see Yagi antennas (PDF).