The LTD 2000 Series
Geolocation Tags

• On-Board Geolocation algorithms provide daily estimates of Latitude and Longitude based on measured sunlight levels for the entire mission, regardless of mission length.
• Daily estimates of Sea Surface Temperature are recorded as a means of augmenting the Latitude by light level estimates when needed.
• Temperature, Depth, and Ambient Light Level data is recorded allowing the tag to double as a TDR or to allow post analysis of Geolocation data.
• Due to an advanced memory management feature, the time series log can be configured to telescope in time. This allows the total storage capacity of the tag to be evenly distributed over the entire mission without sacrificing the temporal resolution of the data for any day that time series data was logged.
• The crystal controlled Real-Time clock aboard each tag is temperature compensated. This results in a clock accuracy of 1 ppm. (~30 seconds / year) allowing for accurate correlation of data for Geolocation and other behavioral analysis.
• Ambient light intensity and external temperature is measured with a field proven "sensor stalk". The stalk allows these measurements when the body of the tag is implanted in the animal. Standard stalk lengths are 27 cm for the LTD 2310, and 10 cm for the LTD 2410; custom lengths are also available.
• The ambient light is band pass filtered at 470nm matching the blue-green color of the ocean. This maximizes the depth at which geolocation can be performed.
• A selection of pressure ranges is available for each tag to match each application.
• The LTD 2310 is designed for 10+ years of service at depths of 2000 meters. The stainless steel housing is specifically designed to prevent salt penetration over long missions.
• The LTD 2310 geolocation tag is now available with an expanded memory option: 16 Mbytes
  

More information on the use of LTD 2000 tags for geolocation studies can be found in the PDF document entitled Locating Tuna in the Open Ocean, available either from our Library page, or directly from here (PDF).

A paper evaluating the performance of the Lotek LTD 2310 archival tag can be viewed either from our Library page, or directly from here (PDF).

Information on inferring the surface irradiance from measurements made at depth can be found in the PDF document Correcting light at depth, available either from our Library page, or directly from here (PDF).

A paper describing a new threshold-free method of geolocation using sun light levels can be found in the PDF document An advance in geolocation by light, available either from our Library page, or directly from here (PDF).

The LTD 2000 series comes with data analysis software, TagTalk 2000, also available directly from our Downloads page.

Other marine and freshwater tag options: