First Signal in Space Analysis of GLONASS K-1

Russia’s global navigation satellite system starts the upgrade to a new level. The first GLONASS space vehicle with a CDMA coded signal was launched in February 2011. The article gives a short overview about all transmitted GLONASS-K1 signals. The main focus of this article is the new GLONASS CDMA signal L3. The signal quality is assessed by analysing the purity and symmetry of the spectrum. The modulation quality and possible distortions are analyzed with the help of scatter plot and analysis of the time domain signal. In a final step the primary and secondary Pseudo-Random-Noise Code of GLONASSK1 L3 signal are retrieved out of the sampled signal itself and compared to the theoretical expected code. Finally tracking results of the GLONASS-K1 L3 signals by using a software receiver are presented.