The article concluded probability distribution functions sum of the squares of the random variables in the non-zero expectations. The resulting distribution function is possible to create an efficient single-step phase ambiguity resolution algorithm in determining the spatial orientation of the signals of satellite radio navigation systems. Obtained thresholds at rejecting false solutions, as well as statistical data of the algorithm.Keywords: probability distribution functions, normal distribution, variance, standard deviation square. DOI: 10.17516/1997DOI: 10.17516/ -1397DOI: 10.17516/ -2016 Most problems in designing, research and operation of electronic equipment operate on a random variable having a normal distribution of probabilities. The value of the normal distribution is characterized by two parameters -the expectation of m and variance D. In practice, very often have to deal with the sum of normally distributed variables. In the case of the independence of these variables as a result of the addition is normally distributed, and the expectations and variances are added. Given that the variance is the square of the standard deviation, the resulting dispersion is the sum of squares of the standard variance of the initial terms. * fateev_yury@inbox.ru †