Methods
Ground Truth Map
All Wi-Fi localization methods utilize maps of indoor environments, generated with computer vision and Wi-Fi antennae. This map will be processed to improve fidelity and optimize system performance.
Subtraction
Wi-Fi readings are given as a value out of 100.
To account for differences in antennae, readings are normalized.
We have a ground truth map of the normalized Wi-Fi readings at every point. Each plot represents a set of readings at a distinct point (9 in all)
Find the Difference between a point on ground truth map and Reading.
Find the difference between ground truth map and reading at every point.
Find the total difference between ground truth map and reading by adding up the differences.
Find the total difference between the ground truth map and each Wi-Fi reading at every point on the ground truth map.
At this point, we have a quantitative measurement of the difference between a Wi-Fi signal reading and ground truth map. The closest match will be the least different, meaning it will have the smallest value of total difference. Looking at the map, one can easily conclude he is closest to the bottom right position (point 9).