# GNSS Multipath Detection Using Continuous Time-Series C/N0
## 4 Testing and Results
### Test Results in The Second Location  
The experiment was performed in a dense urban environment near Tokyo station in Tokyo, Japan, on April 18, 2020. The configuration of the receiver and antenna used in this test was the same as that described in Section 4.1. The car was parked at the edge of the road, and the standard patch antenna was attached to the car rooftop. The sampling rate of the measurement data was 1 Hz. The satellite systems and frequencies used in this test were also the same as those described in Section 2.1. The total data recording period was 1,800 s. Post-processed RTK positioning was used to estimate the precise reference position. The configuration of the target location is presented in Figure 16. The left side of the figure depicts the 3D Google map, and the circle indicates the GNSS antenna location. The right side of the figure presents images around the car. There were three lanes on each side of the road, and several high-rise buildings with different heights were present on both sides.  
The horizontal errors of the DGNSS are presented in Figure 17. The tendency of the errors was similar to that of the previous test results, although the maximum error was substantially larger. The maximum absolute horizontal error in the DGNSS was 175.50 m, and the 90 th percentile value obtained was 31.55 m. The standard deviations in the horizontal direction for E and N were 21.95 and 15.66 m, respectively. The average errors in the horizontal direction for E and N were 6.01 and 5.88 m, respectively. The accuracy was not improved in the case in which different minimum C/N\({}_{0}\) values were set, namely 35 and 40 dB-Hz. In reality, the fix rate was 16.5%, and the correct fixes out of the total epochs were only 9.8%. The standard deviations of the RTK-GNSS with correct ambiguities in the horizontal direction for E and N were 0.013 and 0.012 m, respectively.  
Figure 15: DGNSS horizontal errors using new method.  
The horizontal errors of the DGNSS using our new method are depicted in Figure 18. Note that the vertical scale is different from that of Figure 15. The absolute horizontal error was reduced substantially from the beginning to the end. This indicates that the selection of multipath-contaminated satellites was quite effective when using our new method, and the unfavorable satellites could be rapidly removed in order. The maximum horizontal error was 31.53 m, and the 90 th percentile value obtained was only 9.84 m. The standard deviations in the horizontal direction for E and N were 3.00 and 5.10 m, respectively. The average errors in the horizontal direction for E and N were 0.57 and 2.04 m, respectively. The accuracy was dramatically improved when using the new satellite selection method. Regarding the RTK-GNSS, the fix rate was 26.4% and the correct fixes out of the total epochs totaled 23.0%. The number of incorrect fixes was 3.4%. The standard deviations of the RTK-GNSS with correct ambiguities in the horizontal direction for E and N were 0.012 and 0.018 m, respectively.  
Figure 16: Location of car and detailed images around antenna.  
Figure 17: DGNSS horizontal errors.