nutTAG SEEK - GPS Chip; Time to First Fix; Cold Start; Warm Start

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TAG
AUSTRALIA
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GPS(Chip(
The!GPS!chip!is!the!component!which!receives!and!processes!the!satellite!signals.(
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Time(To(First(Fix(
The!TTFF!is!the!time!taken!for!a!GPS!device!to!acquire!satellite!signals!and!calculate!a!position.!It!is!faster!outdoors!
where!there!are!less!sources!of!interference!for!the!satellite!signals.!(
There!are!three!scenarios!-!Cold!/!Factory!(first!use!or!after!long!distance!travel!/!Long!period!without!use);!Warm!/!
Normal;!and!Hot!/!Standby.(
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Cold(start(
( Device!has!no!estimates!of!satellite!positions!and!must!start!by!acquiring!a!satellite!signal.!Once!found,!device!can!then!
receive!the!almanac!from!this !sate llite;!th e!alm a n ac!is !transmitted!repeatedly!over!12.5!minutes.!Once!obtained,!
position!calculations!can!begin!based!on!visible!satellites.!A!Cold!Start!can!take!up!to!15!minutes.(
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Warm(start((
Device!has!estimates!of!current!time!within!20!seconds,!current!position!within!100km!and!its!velocity!within!25!m/s,!
and!valid!almanac!data.!The!device!must!obtain!ephemeris!data!for!each!satellite!used!in!a!calculation.!A!Warm!Start!
can!take!between!35!seconds!and!3!minutes.!
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Hot(start((
Device!has!valid!time,!position,!almanac!and!ephemeris!data.!This!enables!a!rapid!acquisition!of!satellite!signals.!Hot!
Starts!are!the!fastest!and!can!take!between!1!and!20!seconds.(
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