The EKF is fed with the standard deviation a of the sensors whereas DICPS uses a 3a error bound which corresponds to a 0.99 confidence level.
Figure 4(a) shows the interval error of the DICPS and the EKF.
The EKF is more confident (has a thinner corridor) than DICPS, but the EKF is sometimes inconsistent (does not include the zero value) whereas DICPS is always consistent.
The resulting EKF corridors are larger than those of the consistent DICPS. Consequently, even if it was possible to compute the x value during the localization, the EKF results would not be better than the results of DICPS.
Our algorithm (DICPS) is able to correct the orientation and is real-time executable.
DICPS has been compared to the well-known extended Kalman filter.