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| author | Eric S. Raymond <esr@thyrsus.com> | 2009-08-26 22:24:50 +0000 |
|---|---|---|
| committer | Eric S. Raymond <esr@thyrsus.com> | 2009-08-26 22:24:50 +0000 |
| commit | 81953ce8e31192d659f6405b28ba3db946d69899 (patch) | |
| tree | 1545398cb3b122f6fabc0f568006561735d59146 /gpsd.xml | |
| parent | 9816a5c314e4fd2752d50ab7261de11fb7ffd632 (diff) | |
| download | gpsd-81953ce8e31192d659f6405b28ba3db946d69899.tar.gz | |
Documentation updates.
Diffstat (limited to 'gpsd.xml')
| -rw-r--r-- | gpsd.xml | 9 |
1 files changed, 7 insertions, 2 deletions
@@ -451,8 +451,7 @@ bit, not a per-device one. The j=0 setting is hyper-correct and never displays stale data, but may produce a jittery display; the j=1 setting allows stale data but smooths the display.</para> -<para>(At protocol level below 3, there was no J command. Note, this -command is experimental and its semantics are subject to change.)</para> +<para>(At protocol level below 3, there was no J command.)</para> </listitem> </varlistentry> @@ -1814,6 +1813,12 @@ start of its update cycle (which most consumer-grade NMEA GPSes do not) and it is after 2099, then the century part of the dates <application>gpsd</application> delivers will be wrong.</para> +<para>Generation of position error estimates (eph, epv, epd, eps, epc) +from the incomplete data handed back by GPS reporting protocols +involves both a lot of mathematical black art and fragile +device-dependent assumptions. This code has been bug-prone in tbe +past and problems may still lurk there.</para> + </refsect1> <refsect1 id='files'><title>FILES</title> |