The paper assessed GBAS accuracy performance based on two methods. A GBAS prototype was developed and used to collect and process GPS data. Based on the raw data,two methods called CMC and B values were used to analysis to GBAS accuracy performance. The result of both methods showed consistently that the GBAS prototype accuracy was on the level of GAD -A2 class. Compared with each other,CMC needs to use observations of dual frequencies,however,B values rely on single frequency. Secondly,CMC suppressed short-term multipath errors,and long-term multipath effects remained. B values,however,mainly consist of composite effects of multiple receivers忆errors after averaging across reference receivers,which reflect realistic errors of GBAS corrections as both occupied similar processes. Lastly,sky-maps of root mean squares of CMC and B values reflected surrounding multipath effects of GBAS sites.
