nutTAG SEEK - Glossary and Definitions

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TAG
AUSTRALIA
Glossary$/$Definitions:$
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Technology:!
GNSS(
GNSS!stands!for!Global!Navigation!Satellite!System.!It!is!a!method!of!calculating!location,!velocity!and!precise!timing!
anywhere!on!earth!based!on!the!signals!visible!from!a!satellite!constellation,!using!a!combination!of!trilateration!and!
TDOA!(Time!Difference!of!Arrival)!algorithms.!In!order!to!obtain!a!location,!a!GPS!device!must!be!receiving!signal!from!
at!least!3!satellites.!
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GPS(
GPS!stands!for!Global!Positioning!System!-!a!GNSS!operated!by!the!US!Air!Force,!launched!in!the!1978.!There!are!33!
satellites!in!orbit!at!an!altitude!of!20,180m!
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AGPS(
AGPS!stands!for!Assisted!GPS!-!a!method!of!utilising!internet!resources!to!decrease!the!TTFF!(Time!to!First!Fix).(
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GPS(Almanac(
The!Almanac!contains!Information!on!satellite!trajectory!and!timings,!must!be!downloaded!by!the!GPS!device!for!use!
in!location!calculations.!This !info rm atio n !is!v alid !for!u p !to !180 !da ys.(
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Ephemeris(Data(
Details!on!each!satellite’s!detailed!orbital!information.!Transmitted!every!30!seconds,!and!valid!for!up!to!four!hours.!
Required!for!each!satellite!used!in!a!location!calculation.!