PROJECT TITLE :

Ionospheric bias detection in carrier phase???only ground-based augmentation systems

ABSTRACT:

This work analyzes the design and performance of a planar ionospheric gradient monitor, based mostly on differential carrier part-only measurements between the weather of an antenna array. Tiny ionospheric disturbances are one of the potential threats to aerospace navigation and must be monitored to stop an excessive degradation of the position estimates. A carrier section-primarily based ionospheric gradient monitor enhances bias detection capabilities with respect to monitors that solely exploit pseudorange measurements, provided that the ambiguous nature of the section observations and therefore the measurement error statistics are properly handled. In this work we introduce a statistical take a look at for detecting tiny ionospheric gradients, and we tend to derive the analytical expression of the test likelihood distribution operate for single- and 2-baseline antenna arrays. A theoretical evaluation of the performance of the ionospheric gradient monitor is provided through inspection of the associated acceptance region, which defines the magnitudes of ionospheric gradient that can't be detected with given integrity needs. Because of the integer ambiguity of the carrier-phase measurements, multiple undesirable acceptance regions are produced. We tend to give a methodology to cut back the number and size of such regions.