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GPS data loggers for wildlife, how far have we come?

I started working with GPS collars for wildlife in 1997, 17 years ago….ouch.  For those of you too young to remember, back then GPS wasn’t nearly as advanced as it is now.  For example, we had the choice to set up the GPS timeout at up to 240 seconds!  GPS timeout is the length of time that a GPS is allowed to remain on before being forced to shut off even if it had not acquired satellites and calculated a position by then.

Really, 240 seconds?  That ate up a lot of battery but it was a choice.  Here is what 17 years have yielded…..our newest GPS product will have a timeout option as low as 10 seconds and can be deployed in such a way that the first 3 days of use will always result in hot starts.  Hot starts occur when a GPS receiver has ephemeris data that allow it to know where the GPS satellites are in the sky.  The result is GPS positions sometimes taking as little as 1 second to calculate.  Normally to have hot starts one needs to keep the GPS receiving turning on very frequently.  But this is no longer strictly true.  With a new feature we are including in our FLR II GPS data logger you will be able to deploy with 3 days worth of ephemeris data stored in the GPS data logger.

I have sort of mixed my topics here……there is much more to be said about the 10 second GPS timeout that does not really relate to the ephemeris data but I think I’ll save it for a future post.  For now suffice it to say that we are going to have some very long battery life estimates for GPS devices that weigh in the single digits and part of this will be due to the fact that we are able to use the 10 second GPS timeout when before it would have been much more difficult.

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