Noises in Double-Differenced GNSS Observations

Precise data processing from the Global Navigation Satellite Systems (GNSS) reference station network is mainly based on a combination of double-differenced carrier phase and code observations. This approach allows most measurement errors to be removed or reduced characterized as accurate method. However, creating observation differences between two receivers satellites increases noise observations by factor 2. As result, it impact incorrect definition characteristic results estimation unknowns in positioning model. especially important Multi-GNSS solutions, which integrate measurements different systems, for stochastic parameters may differ significantly. In this paper, authors prepared complex analysis type GNSS (GPS, GLONASS Galileo) observations, both ones, with 1 s sampling interval. The Autocorrelation Function (ACF) method, Lomb–Scargle (L-S) periodogram Allan variance (AVAR) method were used. that obtained weekly set showed that, depending system observation, level its are significantly different. Among measurements, lowest levels GPS C5Q Galileo C7Q/C8Q standard deviations not exceeding ±10 cm, while noisiest C1C C2C signals, had about ±90 cm ±45 respectively. For each signal was very similar ±1.5–3.5 mm. ACF Hz can only treated being correlated time observations; an irrelevant autocorrelation considered intervals greater than 20 s. Depending spectral index k varies range −1.3 −0.2 = 0.0 case data. Using modified deviation (MDEV) specific types determined. All either flicker PM white PM. they all uniquely (GPS (GLONASS).