Single-frequency method of investigation for determination of vertical ionospheric signal delay

The article describes the single-frequency method for determination of vertical ionospheric signal delay. The single-frequency method is based on the single-layer model of the ionosphere. Therefore, it assumed that the ionospheric signal delays in radio visibility zone for each satellite are the same. To verify the functionality of the single-frequency method was created the single-frequency algorithm for determination of vertical ionospheric signal delay. The single-frequency algorithm is based on the increment code and phase pseudorange at the carrier frequency. Using the increments of measurements allows determining signal delay without compensation of instrumental delays and ambiguities without permission. At short intervals, noise error will exceed the useful signal. To exclude this deficiency it is necessary to accumulate measurements. The single-frequency method is realized in real time. To decrease the amount of storage space, the algorithm uses cumulative sum. Interval accumulation is chosen by minimizing of the random error and immutability of trend vertical signal delay in the ionosphere. The purpose of this paper is justification of choice the interval accumulation or filtration coefficient for the single-frequency method. The paper presents results of experimental investigations the single-frequency method for determination of vertical ionospheric signal delay and Klobuchar model. In experimental investigations of the single-frequency algorithm for determination of vertical ionospheric signal delay were considered the main reasons of failure of the algorithm and the ways to solve them. The main component of the budget error of the single-frequency method is the multipath effect and the noise error code measurements. The result of the experiment it was determined that the change in vertical ionospheric signal delay in the interval of 60 minutes at the measurement resolution of 30 seconds are comparable with the noise of the code measurement.