07 Apr Tips from the Experts: Repetition Rates and Animal Behavior: How These Variables Determine Data Transmission
Wildlife Computers Argos tags are governed by a system that specifies how often they may transmit. A key part of this system is the repetition rate, and it is the maximum speed at which a tag can send a satellite transmission.
Although our tags are designed to transmit as soon as they breach the water’s surface, they must obey many parameters, including the repetition rate. If a tag has breached the surface, but less time has passed than the programmed rep rate, the tag will not transmit again. When a tag breaches the surface and an equivalent or longer time has passed than the programmed repetition rate, it will transmit immediately. Both the repetition rate and the breaching of the surface must coincide, in addition to meeting other conditions.
The selection of the proper repetition rate (transmitting every 15 seconds, 30, 45, 60, 90) will depend on the species of animal the individual is tagging. Rates as fast as 15 or 30 seconds require approval from CLS. Some animals, such as turtles and whales, surface for short periods or spend little time at the surface, so repetition rates as fast as 15 seconds may benefit them. Animals that spend more time on the surface or haul out, however, such as pinnipeds, can be programmed with slower repetition rates. A tag’s battery life is affected by the number of transmissions, so an appropriate transmission rate must be chosen for the various animal species. The goal is to maximize data throughput and get a precise location when an animal surfaces or hauls out, without overdoing it.
Due to different animal surfacing times and what satellite coverage is available, there will be spatial gaps between locations and in your data. Choosing the proper repetition rate for your application can help minimize this.
Contact your technical sales consultant if you have questions, or if you would like our recommendations. We can assist in selecting the repetition rate, which will maximize the success of your study.