Analysis of Ionospheric Range Delay Corrections for Navigation in South American Low-Latitude Regions

Ionospheric conditions for South American low- and mid-latitude scenarios are simulated. The performance of an ionospheric correction algorithm on positioning is analysed for this region. This correction is of similar nature to the Satellite Based Augmentation System (SBAS) type algorithm. The mismodelling produced by each ionospheric simulated approximation can be separately quantified: 1) the single layer shell representation of the ionosphere and 2) the simple geometric mapping function. The effects of both components on positioning are evaluated and discussed for periods with different levels of ionospheric activity: winter, summer, and austral spring equinox. The results show that the mapping function is the most important contributor to the ionospheric error. Its effect on the height component is the most important. Besides, on north and east components, the principal error contributor is the Vertical Total Electron Content (VTEC) mismodelling. The application was also tested on real data during a spring equinox of a mid-low solar activity year (2005) and the results are similar and coherent with those obtained using simulated data.