This study aims to develop an efficient multi-antenna GPS technique and quality evaluation approach that can be used to determine the attitude parameters for a moving platform. First, considering the highly dynamic behavior of a moving platform, non-iterative analysis approaches were introduced and their efficiency and reliability were analyzed. Then, a rigorous error analysis approach was established to give definite indications on the obtained attitude parameters. Based on the numerical results from both simulated and real data, it is proven that the proposed approach is capable of giving accurate attitude parameter estimates independently without the need for auxiliary information. Consequently, the multi-antenna GPS system can serve as a reliable resolution of the attitude determination for moving platforms.