A.Y. Shatilov, E.N. Boldenkov , I.V. Lipa
Increasing accumulation time for the pilot component of navigation signal allows improvement of the receiver’s sensitivity and antijam capability in fine acquisition and non-coherent tracking modes. For static user position, the reference oscillator’s drift is the only limiting factor for the correlator accumulation time. The scope of this article is the experimental exploration of oscillator’s drift impact on the SNR and accumulation time problem. The experiment technique and results are presented for a number of popular TCXOs: GK-99TK, GK-206TK, GTXO-83. OCXO was also considered. It is shown for TXCOs that the pilot component correlator accumulation time should be not more than 0.1…0.3 s. Experiment revealed that maximum reasonable accumulation time for a given oscillator is inverse to its Allan deviation at τ = 0.1 s. Also experiment has shown that the considered TCXOs allow tightening of the 3-rd order PLL bandwidth down to 1.3…6 Hz. Generally, minimal working PLL bandwidth is proportional to Allan deviation at τ = 1 s.