Cycle Slip Detection during High Ionospheric Activities Based on Combined Triple-Frequency GNSS Signals
The current cycle slip detection methods of Global Navigation Satellite System (GNSS) were mostly proposed on the basis of assuming the ionospheric delay varying smoothly over time. However, these methods can be invalid during active ionospheric periods, e.g., high Kp index value and scintillations,...
Saved in:
Published in | Remote sensing (Basel, Switzerland) Vol. 11; no. 3; p. 250 |
---|---|
Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Basel
MDPI AG
01.02.2019
|
Subjects | |
Online Access | Get full text |
Cover
Loading…
Summary: | The current cycle slip detection methods of Global Navigation Satellite System (GNSS) were mostly proposed on the basis of assuming the ionospheric delay varying smoothly over time. However, these methods can be invalid during active ionospheric periods, e.g., high Kp index value and scintillations, due to the significant increase of the ionospheric delay. In order to detect cycle slips during high ionospheric activities successfully, this paper proposes a method based on two modified Hatch–Melbourne–Wübbena combinations. The measurement noise in the Hatch–Melbourne–Wübbena combination is minimized by employing the optimally selected combined signals, while the ionospheric delay is detrended using a smoothing technique. The difference between the time-differenced ambiguity of the combined signal and this estimated ionospheric trend is adopted as the detection value, which can be free from ionospheric effect and hold the high precision of the combined signal. Five threshold determination methods are proposed and compared to decide the cycle slip from the magnitude aspect. This proposed method is tested with triple-frequency Global Navigation Satellite System observations collected under high ionospheric activities. Results show that the proposed method can correctly detect and fix cycle slips under disturbed ionosphere. |
---|---|
ISSN: | 2072-4292 2072-4292 |
DOI: | 10.3390/rs11030250 |