Vu Chi Thanh - Post-graduate student, Aerial University of Moscow (State University of Aerospace Technologies)
B.G. Tatarsky - Dr. Sc. (Eng.), Professor, Manager of Vega Scientific Education Center, Head of Department «Radar and radio navigation» of Moscow Aviation Institute (State University of Aerospace Technologies)

This article evaluates the effectiveness of a linear filter which is created by means of fuzzy mathematic bases and which was designed to estimate an in time varying factor of an objective that can be observed in the air. The evaluating activities base on a simulative model which is created under MALAB mathematic environments. Estimated errors of the status vector elements including distance, speed and acceleration are used to prove the effectiveness of the filter. The evaluating results of the output of simulative programs are in form of drawings. Basing on the received results the changes of the squared average error of the status vector elements can be seen clearly in time.