Empirical estimates of the 68% accuracy ellipses/circles for LCs 3, 2, 1, and A.

See text for description of “Methods” column. For the best method, method 5 (boldface), the semimajor axis a was calculated as the 82nd percentile of distribution of longitude errors and semiminor axis b was calculated as the 82nd percentile of the latitude errors, meaning the ellipse so defined encloses approximately 68% of the true positions (note √0.68 is 0.82).