Temporal dependence of GPS cycle slip related to ionospheric irregularities over China low-latitude region

Abstract

[1] Using the global positioning system (GPS) cycle slip (CS) data detected from the observation of six GPS stations in 2001 over the China low-latitude region, the temporal dependence of CS occurrence during solar active year and its cause are analyzed. It is found that the variations of CS occurrence with local time and seasons are obvious. First, the diurnal dependence of CS occurrence detected from six GPS stations is obvious and the distribution of CS occurrence with local time is very similar. On the whole, from 0100 to 1900 LT the CS seldom occurs, and the CS occurrence increases at about 1900 LT, reaches its maximum at about 2200 LT, and then decreases gradually. This temporal distribution of CS occurrence is related with the diurnal variation of ionospheric irregularities above a certain intensity level over the low-latitude region. Second, the seasonal dependence of CS occurrence is also obvious, and the CS occurs more frequently in the equinox months than in other months, which is coincided with the seasonal occurrence of ionospheric scintillation over the Asia-Pacific longitude sector. Besides the synoptic seasonal distribution of CS occurrence, the CS occurrence at some special period exhibits an obvious consistency in these six stations. Finally, the CS occurrence shows some connections with the geomagnetic activity. The cases of inhibiting and generating effect of the geomagnetic activity on CS occurrence are found during the active solar years. It is considered that these dependences of the CS occurrence are related with the variations of the ionospheric irregularities or scintillation in the China low-latitude region.