Unified GNSS Ionosphere

ESA UGI is an open source program package that allows the computation of the vTEC from GNSS observables. The aim is to give to the ionospheric community a starting point for improving the estimates that can be achieved by GNSS. The features of ESA UGI are:

(1) It supports multiconstellation observables coming from: GPS, Galileo and BDS.

(2) It supports only one pair of dual frequency observables for each constellation. Preference: GPS (1W2W); Galileo (1C5Q); BDS (2I7I). Any other unique combination is also possible.

(3) It support 2D and minimum 3D representation of the ionosphere by means of using: VOXEL, MULTILAYER and SPHERICAL HARMONICS.

(4) Input data has to be marked and/or corrected of cycle slips.

(5) It support input of fixed double differences.

(6) It allows the use of regular and semi-irregular grids.

(7) The Output contains the vTEC, the Interfrequency biases (IFB) and the carrier phase ambiguities.