1. Overview

This page describes the circle selection algorithm while calculating results from the Apollonius (AP) method. Details of the AP method can be found here.

2. Objective

The AP method provides multiple results (in the form of a solution set) when calculating the target location using RTT measurements from landmarks. At the moment we manually select the most appropriate result (by comparing the results with geo-ip lat and log records).

We need to devise a method of selecting the most suitable results among those calculated by the AP algorithm.

Once the AP method computes all the results, we analyze them and determine which among them form (or tend to form)

In certain cases the AP method does not return any result. In that scenario we change the landmarks used to calculate the results.

Explanation of the tests:
Two methods were used to optimize the Apollonius results:
1) In the first method, we used all the circles and then one circle with giving closer results relative to Geo IP was considered to be Apollonius circle.
2) In second method, we tried to find out cluster of circles and for this following approach was used:
1) Let's suppose, we obtained n circles using apollonius. Now, we took each of these n circles and for each circle s, we calculated the distance between it's center and the center of all other n-1 circles and summed it. Let we call this sum as Sum(si). Then we took average of this value.
In this way we calculated the average distance value for each of circle and finally one circle with smallest average value was considered as Apollonius circle.

For results please see the attachments.

TODO:
Add description page of Apollonius
Add page describing landmark selection method.