Desert Star Systems is developing a special self-powered “archival tag” – the SeaTag-GEO – to track fish under a NOAA funded project. The idea behind these tags is that researchers would tag a fish and release it. Later, hopefully, someone catches the fish, sees the tag and returns it to the researchers (there is a reward tied to returning the tag).
Unlike other tagging systems that just provide the single fact of where the fish was caught, the Desert Star tag creates daily logs of where the fish has swum. This information can be downloaded from the tag and used to reconstruct a fish’s location over time. With enough data, scientists can piece together the species’ migratory patterns.
Suffice it to say, creating such a tag is no easy feat. Using light to determine location is a problem, especially at certain depths and locations (e.g., what happens during the all-night and all-day periods close to the Earth’s poles?). And, how do you keep a GPS device powered?
Desert Star says it has the solution(s). The company claims that the SeaTag-GEO archival tag is the first to be solar powered and to use geomagnetics for positioning. Power-wise, the SeaTag-GEO uses a little solar cell to keep a 3v aerogel capacitor charged and provide longitudinal data. There is no external connector for the tag. Information is uploaded to the tag via the solar cell, and downloaded using an RF antenna.