Comparative Analysis of Smartphones and Survey-Grade GNSS Receivers for Parcel Boundary Determination

This paper advances the existing body of knowledge on the suitability of accuracy derivable from the use of smartphones for cadastral mapping. Zenvus App software was installed on two smartphones of a different make. A set of dual-frequency GPS Promark 3 receivers and two different smartphones of different make were used for data acquisition. Observations were carried out at the boundaries of ten parcels of land, comprising 46 boundary points. Coordinates of these points were obtained using Differential Global Positioning System (DGPS) observation in static mode and two android smartphones (Samsung A70 and Tecno Spark 3 Pro).  Mean score, root means square error, and one-way analysis of variance was used to show significant differences in the equipment used.  Overall, both the accuracy (mean) and precision (RMSE) were lower than those obtained by Differential GPS. A one-way analysis of variance (ANOVA) was calculated on the values of both X and Y.  For X, the analysis was not significant, F (1, 45)= 0.88, p= 0.419 and for Y, the analysis was also not significant, F(1,45) =0.97, p=0.383. The total RMSE shows that coordinates of points as obtained by the Samsung smartphone (3.368) was more precise than Tecno (4.041). However, the two smartphones (Tecno and Samsung) were less accurate than differential GPS. This implies that there is a 95% chance that the errors in the estimates are less than 6.993m (for Tecno) and 5.848m (for Samsung) respectively. The variation in the observations obtainable with smartphones affects both linear and polygon estimates. The study concluded that the magnitude of these errors is significant in cadastral survey practices and hence not suitable for use. It is recommended that further studies be carried out on the use of the Zenvus app on centimeter grade smartphones probably this could yield a better result suitable for cadastral mapping.