In 1997 we introduced the world's first pop-up satellite tag for tracking fish. Since then thousands of these tags have been used to reveal the ocean-wide movements of large pelagic fishes. Over the last 14 years we have continually developed the tag, adding new features such as our unique SiV™ technology and new data compression techniques with the ability to correct bit errors in the raw Argos messages.
Over the last few years we have been testing many new ideas on variants of the original tag. These have been brought together in this next generation archival pop-up tag. The X-Tag addresses the main request from researchers - it is much smaller, roughly half the size of the original tag, and hence is suitable for use on much smaller species than have been previously tracked with pop-up tags. It is also a direct, lower drag, replacement tag for use in studies already using larger tags.
- SiV™ Satellite-in-View transmission protocol
- Argos II transmission frequency
- Emergency Release below preset depth
- Constant Pressure Pop-off
- Temperature compensated real-time clock
- Embedded checksum with bit error correction capability
- Simple deployment
- Very strong Carbon Fiber housing
- Strong tether attachment point
- Lower hydrodynamic drag
- Smaller physical size
- Lighter weight (40 g in air)
- 15,000 Argos message transmission capability
- 64 Mb non-volatile archival memory
- Longer shelf life
- Higher pressure rating > 3500 psi (2500 m)
Like the original Archival Pop-up Tag, this tag collects data from the sensors and stores them onboard as individual readings of temperature and pressure; it does not "Bin" the measurements, so the data received via Argos can be reconstructed to show a time sequence of the parameter over time ( i.e., time-series data).
Light levels are analyzed onboard the tag with our "Fuzzy Logic" algorithm to determine the time of sunrise and sunset each day. A subset of the data is transmitted through Argos; for deployments up to 4 months readings at 15 minute intervals are transmitted. For deployments exceeding 4 months but less than 8 months, these 15 minute points are replaced with 30 minute points. Similarly, for deployments over 8 months but less than 16 months the points are replaced with hourly points. In each case only the number of data points needed to maintain a full transmission buffer will be replaced. The buffer is transmitted on a pseudo-random schedule to ensure equal distribution of the received data points over the deployment period.
The price of the tag includes data decompression and parsing. Simply send us the complete Argos dataset in DS and DIAG format, together with the pre-deployment test and calibration data and we will extract the sensor readings from it for you. We will then send this back to you in spreadsheet files together with a preliminary analysis. This frees up much of the users' valuable time and allows you to concentrate on interpreting the scientific data. You can even arrange with Argos to have the data sent to us directly via their ADS distribution system.
Once the tag has finished transmitting through the Argos system, data are parsed at our facility and a report is created. We send the report directly to the researcher via email. Turn-around times for reports can vary based on the number of datasets in queue for processing. Generally, data reports are sent within two weeks after the tag has completed its transmission. The reports contain time-series depth, time-series temperature, and daily geolocation estimates (geolocation excluded in high-rate programmed tags). The following link shows an example of some of the data provided in the report.
Photo by Ken Neill