Исследование варианта реализации метода коррекции ионосферной погрешности глобальной навигационной спутниковой системы по фазовым измерениям в различных частотных диапазонах : научное издание
Библиографическое описание:Исследование варианта реализации метода коррекции ионосферной погрешности глобальной навигационной спутниковой системы по фазовым измерениям в различных частотных диапазонах : научное издание / Н. С. Куличкова, К. А. Куличков, А. В. Гребенников. - Текст : непосредственный // Успехи современной радиоэлектроники. - 2017. - № 12. - С. 53-57. - ISSN 2070-0784. Перевод заглавия: Investigation of the implementation of the method of correction of the ionospheric error of GNSS for phase measurements in different frequency ranges
Аннотация:Предложен метод уменьшения погрешности, связанной с задержкой навигационного сигнала при прохождении от навигационного космического аппарата до навигационной аппаратуры потребителя через ионосферный слой Земли. Отмечено, что иносферная поправка рассчитана с использованием разности приращений фазовых псевдодальностей в двух частотных диапазонах. Проведены экспериментальные исследования по оценке ионосферной поправки и ее влиянию на уменьшение погрешности определения координат.
At the present time, the expansion of the use of modern global navigation satellite systems GLONASS and GPS leads to the need to improve the accuracy of navigation measurements. The accuracy of the determination of coordinates and time depends on the accuracy of the pseudorange measurements with GLONASS and GPS signals. The error in measuring pseudoranges is due to a number of factors, the most significant of which are the errors of ephemeris-time provision, the delay of the signal in the ionosphere and the troposphere, the multipath signal propagation. A significant contribution to the error in measuring the pseudo range by the navigational equipment of the consumer (NEC) GLONASS user and GPS pseudoranges is made by the signal delay in the ionosphere, which is caused by the integrated electronic concentration (IEC) along the propagation path of the signal. The influence of the ionosphere on the signals of navigational satellite (NS) vehicles propagating in it leads to phase and group delays. The magnitude of the signal delay in the ionosphere depends on the solar activity, seasonal and daily variations, the elevation angle and azimuth of the NS, and on the latitude and longitude of the NEC GLONASS and GPS. There is a basic (standard) method for determining the signal delay in the ionosphere, implemented in a two-frequency NEC, which measures the difference in the code pseudo-ranges measured by the range-finding code of the NS in the frequency ranges L1 and L2 to find the ionospheric correction [1]. The main drawback of this method is the need to calibrate the inter-band delay of a two-frequency NEC, which is a laborious process, and also the influence on the error in estimating the ionospheric delay of the inter-band delay arising in the NS equipment. An alternative embodiment of the method for correcting the ionospheric error is based on measuring the difference in phase pseudo range increments for the L1 and L2 bands. The calculation of the ionospheric correction consists of two stages: the calculation of the vertical delay of the navigation signal in the ionosphere and the determination of the change in the ionospheric correction. To confirm the effectiveness of the presented method, measurements were taken at a point with known coordinates. The obtained results showed that when using ionospheric correction, the altitude estimate shifts to the true value, and the standard deviation changes insignificantly and is caused by a random error having a quasi-harmonic (wavy) character, with a mathematical expectation close to zero. The presented variant of the ionospheric error correction method showed that the ionospheric correction has a very small standard deviation not exceeding 1 cm, which makes it possible to compensate for the ionospheric delay without introducing an additional random component into the navigation measurements. Use in calculation the increment of the measured parameters makes it possible to use the phase two-frequency method without preliminary calibration of navigation equipment.
