Three frequency linear combinations for Galileo

The consideration of linear combinations of phase measurements is an effective method for the resolution of carrier phase ambiguities. Examples of classical combinations are the super-widelane and widelane combinations. The main aspects are to increase the wavelength and to reduce the influence of the ionosphere, while keeping the noise amplification moderate. In the present paper, a new type of combinations is introduced. These combinations leave the geometry invariant. A particular class of such combinations is discrete and finite. An exhaustive search leads to interesting new widelane combinations. Some have very long wavelengths, e.g. 29.31 m. Others have excellent ionospheric suppression, e.g. 28.78 dB at a wavelength of 3.256 m. The best ionospheric suppression of 38.30 dB is obtained for a narrowlane combination with a wavelength of 2.69 cm.