Accuracy estimation of alternative positioning in navigation

Alternative positioning navigation by DME service network is used in many cases on-board of aircraft. This problem is topical in case of bad accuracy of GNNS, spatially during takeoff or landing phases of aircraft flight. In the paper, an accurate approach of positioning by data from DME with support of all available DMEs signals in particular point of airspace has been discussed. An availability area of Ukrainian DME service network for altitude of FL320 has been evaluated. Dilution of precision coefficient for geometrical factor estimation in accuracy calculation of positioning by DME network for Ukrainian airspace was used.