The deployment of the European global navigation satellite system, Galileo, with its specific signal structure, encourages the development of new signal processing methods at the receiver level. In particular, the structure and characteristics of the Galileo E1 OS signal make its acquisition not easy and require optimization to reduce computation time and complexity. The present article proposes a novel Galileo E1 OS signal acquisition method. The background technique to do so is taken from an existing GPS L1 signal acquisition method, the Double Block Zero Padding (DBZP). This paper provides the detailed description (including the mathematical model) of the DBZP and shows its theoretical performance in terms of probability of detection and number of operations. Based on this analysis, the paper proposes an improvement of the DBZP for signals, like Galileo E1 OS, that include frequent bit transitions. This technique is compared with a reference acquisition method, and shows very good and interesting results demonstrating the potential of this innovative Galileo E1 OS signal acquisition method.