I.V. Lipa - Post-graduate Student of Department of Radiotechnical Systems, National Research University "MPEI"
E.N. Boldenkov - Ph.D. (Eng.), associate professor of Department of Radiotechnical Systems, National Research University "MPEI"

In urban environment navigation satellites visibility is quite poor. Due to this fact tracking losses are frequent. In situation of signal reacquisition a lot of a-priory information about signal parameters is available. Maximum user velocity in the city is limited. Therefore delay and frequency uncertainty is also limited. The article is focused on the signal acquisition performance analysis with respect to this a-priory information. Signal acquisition performance depends highly on the size of acquisition area. Large acquisition area requires a lot of parallel acquisition channels to implement. The problem is the false detection probability. The larger is the number of parallel channels the more is false probability. Due to this one need to make detection threshold higher. This decreases true dectection probability, Corresponding losses in terms of signal to noise ratio are considered in the article.