Correction of cycle slips in stand-alone GPS receiver data for phase scintillation index evaluation
Résumé
The present paper deals with the evaluation of phase scintillation indices (such as sf) from GPS receiver data. More specifically, the problem of cycle slip correction is addressed. Cycle slips are encountered if, by accident, a signal loss of lock occurs. Then, the receiver integer phase counter is reinitialised which causes a jump in the accumulated phase measurements [1]. Cycle slips usually have a deleterious effect on scintillation index evaluation as depicted in Fig. 1. Although algorithms for cycle slip correction exist, most are applicable only to differential GPS data [2], [3], [4], [5]. The present paper deals with the problem of cycle slip correction for dual-frequency stand-alone receivers [6]. Such configurations are encountered in particular when GPS receivers are used to monitor ionospheric activity on a regional or global scale [7]. An algorithm is proposed that corrects for cycle slips as small as a few wavelengths in range