# Accuracy of Code GNSS Receivers under Various Conditions
## 5 Conclusions
The deviations for the N component did not exceed 11 m, while for the E component, they were within 7 m. It was also observed that the G_1 receiver using the GPS system obtained a higher accuracy (up to 12 m) during the height survey than the G_2 receiver (GPS+GLONASS), which obtained deviation values ranging from 28 to 55 m. When analyzing the linear measurement results, it was noted that the handheld receivers obtained better results compared to the cell phones. The Garmin G_2 receiver using the GPS+GLONASS mode measured horizontal coordinates with a higher accuracy (by 1 m) compared to the G_1 (GPS) receiver, while in the case of height measurement, the G_1 instrument obtained smaller deviations in the U component. When analyzing the surface measurement results, smaller deviations in NE components determined by handheld receivers than by cell phones were observed. The measurement route was surrounded by trees more closely than in the case of the point and line objects. During the measurement, the loss of the measurement signal of the X_1 receiver was noticed, which was characterized by the registration of the last recorded point until the end of the measurement. Phone X_2 positioned the user with an error of no more than 15 m for the N component and 12 m for the E component. The horizontal coordinate errors ranged from 5.1 to 5.6 m, while the standard deviation was 3.2 m. The X_3 smartphone received deviation values of up to 15 m for the N component, and up to 13 m for the E component. Horizontal coordinate errors ranged from 4.4 to 5.5 m, while the standard deviation ranged from 2.8 to 3.1 m. The positioning results of the cell phones during the surface measurement were very similar, with high consistency and repeatability; errors were distributed uniformly, as with a random distribution. The G_1 receiver using GPS mode was positioned with an error of no more than 9 m for the NE components and 14 m for the U component. Horizontal coordinate errors ranged from 2.6 to 2.8 m, while the standard deviation ranged from 1.8 to 1.9 m. The receiver using the GPS+GLONASS mode received deviation values of up to 8 m for the N component and up to 6 m for the E component. Horizontal coordinate errors were 1.9 m, while the standard deviation ranged from 1.4 to 1.6 m. The deviation in the elevation component ranged from 25 to 54 m. The Garmin receiver plots for the surface measurement were similar for the NE components, while for the height coordinate, the deviations in the U component of the G_2 receiver were larger by up to 40 m.  
The most favorable results were obtained for the static point measurement, and the worst results were obtained for the linear measurement that took place in motion. The results of each measurement are presented in plots of the horizontal component deviations (NE) and a line plot of the altitude component changes (U) for the travel receivers. The mean errors and accuracy of the receivers were also plotted. The tested GNSS code receivers did not allow for accurate measurements in conditions of limited visibility. While during a point measurement, it would be possible to obtain satisfactory results after an appropriate selection of the obtained data, it is not possible in the case of measurements in motion. A better performance of the cell phones was observed during the point measurement than the GPS-only Garmin receiver. The measurement with smartphones was consistent, while, in the case of travel receivers, it was noted that more satisfactory results were obtained by the receiver working in GPS+GLONASS mode. The value of the average error of horizontal coordinates was 3 times smaller compared to the handheld receiver using GPS only. During linear and surface measurements in motion, handheld receivers achieved better accuracies (by about 5 m) than cell phones. The measurement was nonuniform and unstable.