Trip Odometer vs Tracklog Distance
Some commonly asked questions regarding the Garmin GPSr Trip Computer
- "Why is the Trip Computer odometer distance greater than my
"Why is the Trip Computer odometer distance less than my
"Which is correct?"
While these questions are easy to understand, the answers will require some explanation regarding Garmin GPSr recording functions.
- A Tracklog consists of a series of track points (or bread crumbs) recorded by your GPSr.
Garmin GPSr allow the user to adjust how and when track points are recorded:
- Distance (records new track points at a specified distance, regardless of time elapsed)
Time (records new track points at a specified frequency, regardless of distance traveled)
Auto (records new track points as needed, determined by direction of travel and velocity)
- Time (user selected time interval between recorded track points)
Distance (user selected distance interval between recorded track points)
- The Trip Computer records the total distance traveled and displays the information in the
Trip Odometer data field.
The Trip Odometer distance will increase only when the GPSr position changes.
The Trip Odometer is updated at a fixed frequency of 1Hz, or once every second.
The Trip Odometer can be reset to zero at any time.
- Longer Tracklog recordings will exhibit greater accumulated discrepancy than shorter
For clarity, only a very short section of Tracklog is displayed in this example.
Every Tracklog has a Start Point (A) and End point
The GPSr will travel from Point (A) to Point
The actual path traveled between Point
(A) and Point (B) requires navigating some obstacles:
The Tracklog records Track Points at the user specified interval:
The Tracklog distance traveled between point
(A) and point (B)
is calculated between recorded Track Points:
The Trip Computer records Track Points at an interval of one per second (1Hz):
The Trip Computer distance traveled between
point (A) and point
(B) is calculated between recorded Track Points:
The calculated Trip Computer distance is greater than the
- Tracklog distance vs Trip Computer odometer will vary based on Track Record settings for each GPSr device.
More Track Points generally translate into improved accuracy.
Two options exist to achieve a Tracklog distance that closely resembles the Trip Computer odometer at Point
- Set Track Record Method to Time
- Set Track Record Interval to 00:00:01, or once per second (1Hz)
- Clear Current Track and Reset Trip Computer Odometer at Point (A)
If your GPSr has a 'Trip Recording' option in the tracklog recording setup menu, do not choose 'Always'