Solar Argos/GPS PTTs combine high-accuracy GPS technology with solar-powered, rechargeable batteries to yield long-term understanding of migration and fine-scale habitat use.
Solar-powered Rechargeable Battery
Solar power frees our PTTs from the lifetime limitations of primary lithium batteries. Because these PTTs can be continually recharged with solar energy, they have the potential to run for years, making them well suited for long-term studies.
The solar-recharging process is carefully controlled by an internal microprocessor to optimize power distribution and enable nighttime transmissions (as opposed to less-sophisticated devices where transmissions occur only when the solar cells are exposed to light).
High-quality GPS Locations
Latitude and longitude coordinates within ±18 m.
Altitude positions (3D Firmware only) within ±22 m.
GPS fixes also include course and speed data.
2D and 3D Firmware Options
3D Firmware: Solar Argos/GPS PTTs include (standard) 3D Firmware which records latitude, longitude, altitude, course, and speed data for each GPS fix.
Each transmitted message includes data from 3 GPS fixes, starting with the most recent and continuing backwards until the previous date of transmission (often with some overlap). This sequence of data is sent repeatedly during the transmission windows of that day.
2D Firmware: All Solar Argos/GPS PTTs (except the 17g model) can alternatively be programmed with 2D Firmware which collects only latitude and longitude data.
Each 2D message contains data from 5 GPS fixes taken at the same hour for each of the last 5 days. When data are uploaded to Argos more frequently than every 5 days, there is greater redundancy in data transmission which helps minimize potential for data loss.
Programmable Duty Cycles
Each transmitter is programmed with two independent, user-defined duty cycles. The first cycle defines the hour(s) (solar/local time) when the PTT will take a GPS fix. The second cycle commands how often the PTT will transmit the stored GPS data through the Argos system — typically, this is every 3 days.
Our unique SiV™ technology aligns the timing of transmissions with times when a satellite is most likely passing overhead. This helps conserve battery power and increases the likelihood of the satellites receiving the transmitted messages.
Ground Track (GT™) Option
PTTs can be programmed with Seasonal and/or Mortality GT™. This feature enables a PTT to also function as a conventional radio transmitter, emitting a UHF frequency at prespecified times that can be heard via a Yagi antenna and receiver. GT™ is helpful for locating birds in real time, pinpointing injured/dead individuals, and recovering downed transmitters.
Note: Though suitable for most applications, we do not recommend solar-powered transmitters for use on species that are likely to preen feathers over a backpack attachment or inhabit locations/latitudes where sunlight is limited, as these conditions may inhibit proper battery charging.
* While conventional thinking suggests choosing a transmitter weighing <3% of a bird's weight, we are aware that birds routinely carry weights greater, and sometimes less, than 3% of their body weight. Because each species is different, it is crucial that you review the literature on your study species and use proper discretion to determine the appropriate transmitter model for your project.
** Based on a 3-day duty cycle transmission schedule.
*** Relative GPS fix reserve based on battery size and operating current of Solar Argos/GPS PTTs.
† Relative solar array capability based on solar array size and housing optimization of Solar Argos/GPS PTTs.
†† Available only for patagial attachment.