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| author | Sanjeev Gupta <ghane0@gmail.com> | 2015-04-17 22:54:53 +0800 |
|---|---|---|
| committer | Eric S. Raymond <esr@thyrsus.com> | 2015-04-18 01:01:30 -0400 |
| commit | 413d152aa0fd3945ad0debec161bb508ae9d393f (patch) | |
| tree | ac540795fd178d489e09335a60cdba9d0fe9eb6b /www | |
| parent | bf0081524f20e85b8de0733e129bce8b5dc0090f (diff) | |
| download | gpsd-413d152aa0fd3945ad0debec161bb508ae9d393f.tar.gz | |
Define TTFF
Diffstat (limited to 'www')
| -rw-r--r-- | www/gps-hacking.html | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/www/gps-hacking.html b/www/gps-hacking.html index 3bdacc95..bee02742 100644 --- a/www/gps-hacking.html +++ b/www/gps-hacking.html @@ -383,12 +383,13 @@ feel for what your GPS has to say, and how often it says it.</p> <h1>Locking and Loading</h1> -<p>The time required for a GPS to get a fix can vary from under 15 -seconds up to just under 30 minutes (actually, 29 plus calculation -time). The main factors affecting this latency are (a) whether it has -an almanac available, (b) whether it has satellite ephemerides -available, and (c) whether it has recent fix available. Of course the -quality of signal at your location matters as well.</p> +<p>The time required for a GPS to get a fix (Time To First Fix (TTFF)) +can vary from under 15 seconds up to just under 30 minutes (actually, +29 plus calculation time). The main factors affecting this latency are +(a) whether it has an almanac available, +(b) whether it has satellite ephemerides available, and +(c) whether it has recent fix available. +Of course the quality of signal at your location matters as well.</p> <p>If a GPS has not been on for several months, then it has no current almanac available. It was to wait to download one before it can |