Movement & Time
Tracks are not points — the order and the clock are the data.
A GPS track looks like a table of points until you try to measure anything: the speed between two fixes depends on the sampling rate, the total distance depends on how much noise you left in, and a timezone-naive column sorts a night shift into the wrong day. These guides cover what makes a trajectory different from a point layer, where GPS error comes from and what it does to derived quantities, cleaning and resampling a track, splitting it into trips and stops, map-matching it to a street network, and aggregating many tracks into flows.
Cleaning comes before measuring throughout, because a single bad fix contaminates the two legs either side of it. The useful property is that the check is physical: a leg implying 300 km/h is wrong regardless of what the data claims, and that is the only assertion in this subject the data cannot argue with.
Start here
The cornerstone guide — the whole workflow end to end. Everything after it goes deeper into one part of it.
Step 1 Trajectories Explained: What Makes a Track Different from Points trajectories explained Begin the path →The full path, in order
The concepts underneath the work, then each task, then the errors that task produces. Work down, or jump to the step you need.
- Sampling Rate and Gaps Explained: How Often Is Often Enough gps sampling rate explained 🧭 Concept
- GPS Error Explained: Why Your Track Wanders gps error explained 🧭 Concept
- How to Load GPS Tracks into Python as Trajectories load gps tracks python ⚙️ How-To
- My Time Column Sorts or Joins Wrongly spatial time column timezone errors 🔧 Fix
- How to Clean a GPS Track: Outliers, Duplicates and Jumps clean gps track python ⚙️ How-To
- My Track Has Impossible Speeds or Teleports track impossible speeds 🔧 Fix
- How to Calculate Speed, Distance and Direction Along a Track speed distance direction track python ⚙️ How-To
- Stops, Trips and Segmentation Explained stops trips segmentation explained 🧭 Concept
- How to Split a Track into Trips and Stops in Python split track into trips python ⚙️ How-To
- How to Resample and Interpolate a Track to a Fixed Interval resample gps track python ⚙️ How-To
- How to Map-Match a GPS Track to a Street Network map match gps track python ⚙️ How-To
- How to Aggregate Movement into Flows Between Zones aggregate movement flows python ⚙️ How-To
- How to Animate Movement Over Time in Python animate movement python ⚙️ How-To
Topics this path covers
A path is a route; a topic is everything the site has on a subject. Open a topic to see the guides this path skips.