A gps track log is a collection of track points along the course of a route. It’s essentially a bread crumb trail of the path of the route to be navigated. Track logs can tell us where we have been and therefore how to get back to where we started. More importantly, if prepared in advance, a track log can tell us where we need to go.
Track Logs are most often created by a GPS instrument as the user navigates a desired route or path. It’s a recording of the path navigated. Not all GPS instruments utilize track logs. Some instruments only give the user an active track log with no ability to save the track log as an individual file.
The various GPS instruments handle track logs in different ways. Even within a manufacturers product line, the track log functions are different mainly due to product evolution. Some instruments only allow the user to work with an Active or Main track log. Other units allow the user to save track logs.
The Garmin GPS III+ and earlier units do not allow tracks to be uploaded to saved logs, so all uploaded tracks go to the main or active track log. It’s important to remember to save each individual track log from the Active log if you intend to have multiple track log files available on the instrument.
There are limits on how many track points can exist in a track log file. Many units allow more track points in the active log than the saved log. When a track log is saved the number of track points (resolution) is reduced to a number less than or equal to the maximum number of units allowed for a saved log. Early Garmin units allowed 250 track points in a saved log. Some of the higher end units like the Garmin 176C allow for 500 track points in a saved log file.
On the later Garmin units, you can load track logs directly into saved logs in the gps instrument. These files must not be over the maximum number of track points otherwise the file will be truncated. It’s a good idea to have track logs stored on your computer in a reduced format (less than or equal to the maximum number of track points allowed in a stored track log for the intended instrument).
Also, you must keep in mind that any track uploaded which does not have the name ACTIVE LOG will be sent to a 'saved track' log on the Garmin units capable of uploading to stored log files.