Abstract
Continuity is an index to describe and measure the performance of the satellite navigation system as well as position accuracy. In order to evaluate continuity, a possible way is computing MTBF (Mean Time Between Failures) thru dividing the total operation time by the number of failure events. However, especially in case of satellite navigation, the number of failure events is quite small to estimate reliable value of continuity unless observation period is set to unrealistic length. This technical report gives a practical method to estimate lower and upper limits of continuity for a given level of reliability.