TSEP positioning accuracy evaluation approach applied in 4D guidance

As humans exploration activities increase in deep space and identification needs of space navigation equipment, traditional probability indicators and evaluation approach cannot meet the system requirements. Three sphere error probabilitiy (SEP) calculation methods were deduced and induced: triple integral equation algorithm, χ² distribution approximation algorithm, and maximum likelihood estimation (MLE) optimization algorithm. Combined with the two statistical test schemes, time SEP (TSEP) accuracy evaluation method was raised. Simulation and test verification shows that: TSEP method of positioning accuracy of space equipment gives a relative comprehensive evaluation, the scheme is viable, compatible with traditional method of calculating indicators and takes full advantage of single test data, test simple. Three SEP algorithms can all compute SEP, maximum relative error of no more than 7%; slightly conservative the χ² distribution approximation is recommended; MLE calculation values can be used as initial values of the integral operator in order to reduce the number of integral operation, in quickly gets the true value.