<para>
	This is the log format output by factory-installed Honda/Acura (Alpine) Navigation Systems 
	in (at least) 2006 models and newer.  (Though I've seen indirect data that says that Acura 
	nav systems at least as far back as 2004 use it too)
</para>
<para>
	This format is definitely known to work with the following model cars specifically:
</para>
<simplelist columns="1">
<member>
	2006 Honda Civic Hybrid
</member>
</simplelist>
<para>
	Logging may be enabled by simultaneously holding down the MAP/GUIDE, MENU, and CANCEL
	buttons for 3-5 seconds, then selecting "Functional Setup", "Log Data".  A PCMCIA card
	must be inserted into the system (behind the Nav LCD) for logging to work.  (The system
	can read MP3/WMA files on this card and will also write logs to it.  Generally, a
	PCMCIA to CF or PCMCIA to SD adapter is used with a corresponding CF/SD card)  With
	logging successfully set up, the system will create a directory named "VPlog" off the
	root of the card.  Inside this directory, files will be created with names corresponding
	to the date and time of engine start, in GMT.  (YYMMDD_HHMM.vpl)
</para>
<para>
	The VPL format contains quite a bit of data, much of which remains undecoded.  This format
	currently reads only lat/lon, altitude, speed, heading, date/time, visible sats, HDOP and
	VDOP.
</para>
<para>
	Generally, the layout of the format seems similar to NMEA, with discrete sentences
	containing different fields of data, followed by a 1-byte XOR'd checksum.  Some sentences
	are generated only once per engine start, others every few seconds, many every second,
	and a few on the order of five and in one case, up to twenty five times per second.  All data in
	the file is written in ASCII; most of it simply as hexadecimal characters.  Most
	fields are fixed width, though a few can be variable.  (Those that are variable
	have a field count as the first field after their sentence identifier)  Currently,
	only the '75'-sentence is processed (and only about 70% of it), though this provides all
	the data necessary for position information.

	Some fields in other sentences have been decoded, but they are not currently processed.
	Information on the data in these fields can be found in vpl.c.
</para>
