Garmin GPS Data- Defined

This article details how the GPS data is presented, and how to interpret it.

Sample GPS data below:

GPS 1

GPS 2

Variable in the GPS  dataset  

Meaning

act_index 

Index of activity (#)

start_time 

Unix Start time of the activity

start_time_offset 

Offset to add to start time to derive the “local” time of the device that captured the data (hr)

start_time_local 

Local  start time of the activity

activity_type 

Text description of the activity type

clock_duration_in_seconds 

Length of the monitoring period of “clock time” of this sample (sec)

elevation_in_meters 

Elevation (m)

heart_rate 

Heart rate (#/min)

latitude_in_degree 

Latitude in decimal degrees (DD)

longitude_in_degree 

Longitude in decimal degrees (DD)

moving_duration_in_seconds 

The amount of “timer time” during which the athlete was moving (above a threshold speed) (sec)

speed_meters_per_second 

Velocity (m/s)

steps_per_minute 

Step frequency (#/min)

time_duration_in_seconds 

Length of the monitoring period of “timer time” of this sample  (sec)

total_distance_in_meters 

Total accumulating distance of this activity (m)

 

*Tip:
In all cases, movingDurationInSeconds <= timerDurationInSeconds <= clockDurationInSeconds.

For example, a user is going for a run. They start the timer at exactly noon. At 12:30, they pause the timer (either manually or using auto-pause) to stop and chat with a friend, and at 12:35 they resume the timer. 

At 12:40 they stand still for 2 minutes, waiting on a traffic signal at a busy intersection, then finish their run and manually stop the timer at 1:00 pm. 

clockDurationInSeconds = 60 minutes (12:00 - 1:00)
timerDurationInSeconds = 55 minutes (12:00- 12:30 + 12:35 - 1:00)
movingDurationInSeconds= 53 minutes (12:00 - 12:30 + 12:35- 12:40 + 12:42 - 1:00)

Note: In order to activate GPS data collection, participants must manually click "start activity" and "end activity" on the watch face for the necessary time period (e.g. once they leave their home). The activity can last for several hours, however, they must remember to click "start activity" in order to activate the GPS. 





Last updated: March 1, 2022