Files In Gtm Format; Files In Text Format - GPS TrackMaker Reference Manual

2.2 Files in GTM Format

The GPS TrackMaker® default file format has the extension GTM (initials for GPS TrackMaker). This format
stores all Waypoints, Tracklogs and Routes as well as information related to the screen display, background and
grid color, Waypoint text, User-defined text, etc. Digitized images are also included in the GTM file.
The GTM file was developed for compact data storage and enhanced recording speed when compared to Text
formats. This is a binary format with the following structure:
Saving the Characteristics of Each Image
The data of each image is saved sequentially in the GTM file with variables of 6 decimal places.
Saving the Waypoints
Waypoints are saved sequentially in the GTM file with the latitude and longitude values always in decimal degrees
with 13 decimal places of precision. The altitude in relation to the sea level is also saved with 13 decimal places of
precision.
Saving Tracklogs
Tracklogs are saved with latitude and longitude values in decimal degrees with 13 decimal places of precision. The
altitude in relation to the sea level is saved with 6 decimal places of precision.
Saving Routes (Routes)
Routes are saved using the same format as Waypoints.
Saving Digitalized Images of Maps and Photos
Images are saved byte to byte in the end of the GTM file. The image file is attached in the original extension that
it was loaded. Thus, images in GIF or JPG format will occupy less space than BMP files inside the GTM file.
Note: At www.trackmaker.com you will find a detailed specification of the GTM format.
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