Calculating Metrics for Spatial Data Quality

Below, you’ll find a map layout that illustrates the waypoints recorded, along with the average location and the circular buffers representing 50%, 68%, and 95% precision estimates.

Horizontal Precision: 

    50th percentile: 3.1 meters

    68th percentile: 4.5 meters 

    95th percentile: 14.8 meters

Horizontal Difference: 3.29 meters

When it comes to GPS data, horizontal accuracy refers to how close the recorded GPS points are to the true location, or the reference point. Essentially, it measures the difference between the average of all recorded points and the actual position we're trying to measure. Horizontal precision, on the other hand, is about consistency. It tells us how closely the GPS points are clustered together, regardless of whether they are close to the true location. A high precision means the points are tightly grouped, while a low precision indicates they are more spread out.

In my analysis, I found that the horizontal precision gives a good indication of how consistent my GPS readings were. By comparing this with the horizontal accuracy, I can determine how reliable my GPS unit is, both in terms of consistency and how close it gets to the true location.