Our company began with Battery Powered PTTs. These devices continue to prove dependable and effective for specialized applications involving birds of medium to large size. Battery Powered PTTs are powered by primary lithium batteries and are especially useful for studies where solar-powered battery recharging may not be possible.
| Minimum Bird Weight* |
Estimated Transmission Lifetime** |
GPS-Equipped | |
|
1500 grams |
~1000 hours |
|
|
3167 grams |
~2000 hours |
|
|
3500 grams |
up to 3 years*** |
|
Argos Doppler Locations
All Battery Powered PTTs transmit messages to the Argos satellite constellation. As
a satellite passes overhead and receives those messages, a PTT's
location is estimated using the perceived Doppler shift in signal
frequency of successive transmissions. Triangulating PTTs' positions in this manner yields locations which are then categorized into "location classes" (LC) based upon their estimated accuracy. Over two-thirds of Argos locations provided by MTI PTTs are in the top three location classes:†
LC3: <250 m radius
LC2: <500 m radius
LC1: <1500 m radius
Please note that Battery Powered 45g and 95g PTTs are not equipped with GPS.
Programmable Duty Cycles
PTTs are programmed with a user-defined duty cycle that dictates when the device will turn ON to transmit and OFF to conserve power. The customizability of these transmission intervals allows PTTs to best accommodate the activity of the species being studied and the project objectives, as well as to budget the battery life of the PTT over the study period, thus extending the usable lifetime of the transmitter.
High-quality GPS Locations with 2D Firmware (105g LC4™ only)
Latitude and longitude coordinates within ±18 m.
The 105g LC4™ PTT is programmed with 2D Firmware which collects latitude and longitude data only. Each 2D message contains data from 5 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, ensuring a high percentage of data is received.
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 study subjects, and recovering downed transmitters. Please note that the additional power required for GT™ will reduce the operational lifetime of a PTT.
* 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.
** Estimated transmission lifetimes based on an 8 hours ON / 48 hours OFF duty cycle.
*** Maximum transmission lifetime possible with standard duty cycle of 1 GPS fix per day and transmission to Argos every 10 days.
† Based on 2016 internal test data.
