@article {98, title = {Assessment of NeQuick ionospheric model for Galileo single-frequency users}, journal = {Acta Geophysica}, volume = {61}, year = {2013}, month = {12/2013}, pages = {1457-1476 }, type = {Research Article}, abstract = {

In signal-degraded environments such as urban canyons and mountainous area, many GNSS\ signals are either blocked or strongly degraded by natural and artificial obstacles. In such

scenarios standalone GPS is often unable to guarantee a continuous and accurate positioning\ due to lack (or the poor quality) of signals. The combination of different GNSSs could be a

suitable approach to fill this gap, because the multi-constellation system guarantees an improved\ satellite availability compared to standalone GPS, thus providing enhanced accuracy, continuity\ and integrity of the positioning. The present GNSSs are GPS, GLONASS, Galileo and Beidou,\ but the latter two are still in the development phase. In this work GPS/GLONASS systems are\ combined for single point positioning and their performance are assessed for different\ configurations. Using GPS/GLONASS multi-constellation implies the addition of an additional\ unknown, i.e. the intersystem time scale offset, which requires a sacrifice of one measurement.

Since the intersystem offset is quasi-constant over a short period, a pseudo-measurement can be\ introduced to compensate the sacrifice.

The benefit after adding a pseudo-measurement has been demonstrated in a vehicular test.

}, keywords = {Galileo, GNSS, ionospheric models, Klobuchar, NeQuick}, issn = {1895-6572}, doi = {10.2478/s11600-013-0116-2}, url = {http://dx.doi.org/10.2478/s11600-013-0116-2}, author = {Angrisano, Antonio and Gaglione, Salvatore and Gioia, Ciro and Massaro, Marco and Robustelli, Umberto} }