Calculation and Analysis on Integrity Threshold Based on Non-Gaussian Distributing

The precondition of integrity calculating equation is usually based on the Gaussian distribution for pseudo range errors.When the assumed Gaussian distribution of range error is contaminated,the calculation results will not protect user position error anymore which will result in additional integrity risk.The integrity equation based on Non-Gaussian distribution was proposed and analyzed.The definition of probability overbounding and two models of multipath errors were introduced.A Gaussian distribution was adopted to overbound the probability of the Non-Gaussian distribution,and the new inflation variance scale was calculated to substitute the variance scale based on Gaussian distribution.The integrity equation was calculated using the new variance scale to gain a safer vertical protect level and horizontal protect level avoiding the additional probability of hazard mislead information and make the integrity equation to be more rigorous in theory.Through the simulation and analysis it is shown that both of the improved integrity equations could Gaussian probability overbound the error which is contaminated,and the first improved equation is more conservative than the second one,and the second improved equation is more optimal and lead to a better availability and continuity.