TK1 specification

A TK1 file is made up of a 1024 bytes header followed by the data and ends with some binary garbage. The files are little endian, so pay attention on non-intel machines or java.

Header

Offset	type	bytes	description	default/example
0x0000	String	16	TK1 Fileformat identifier, null terminated
0x0010	Float	4	Hardware version	1.1
0x0014	Float	4	Software version	1.305
0x0018	Float?	4	Log format version?	1
0x001C	Int32	4	Unknown..., but 0x41BF1000 seems to work	0x41BF1000
0x0020	Int	4	Total number of points	9987
0x0024	Float?	4	Null?
0x0028	String	40	Name of gps device, null padded	WBT201
0x0050	String	40	Serialnumber of gps device, null padded	YYMM1234567890
0x0078	String	20	Date and time of read out, null terminated	2007_12_19_12:07:47\0
0x008C	Int	4	Offset of end of data block in bytes (decimal)	160816
0x0090	Int32	4	Number of tracks	25
0x0094	??	876	Null padding

Data

The data block consists of records, one per point. Each record is 16 bytes long, so the size of the data block should be:

Size data block = Total number of points * 16

The offset of the end of the data block is 1024 + Size data block bytes + 1. A record has the following fields:

Offset	type	bytes	description	default/example
0	bitmask	2	Flags	0000 0001 0000 0000
2	time	4	Timestamp	521198371
6	Int32	4	Latitude * 10.000.000	525152016
10	Int32	4	Longitude * 10.000.000	54818666
14	Int16	2	ALtitude	16

The flags are as follows:

Flags && 0x01 => Track start
Flags && 0x02 => Waypoint
Flags && 0x04 => Overspeed

The last point seems to be duplicated with an invald flag.

The datasection is ended with a list of track information, each track takes 24 bytes.

Offset	type	bytes	description	default/example
0	Int32	4	Track number	1
4	Int32	4	Offset in file	0x0400 0000
8	Int32	4	Number of points in track	397
12	Int32	4	Time	3374
16	Double	8	Distance/1000 in TK2 units = slightly more than km...	0.022