## 3 Results  
In order to verify the presented methodology for the correction of coordinates obtained by the MSM method, a series of both satellite and accelerometric measurements were carried out as well as additional reference measurements using a manual track gauge. A tram line fragment consisting of a curve with a cart and the adjoining straight sections was selected. For the measurement of accelerations, an MPU-6500 triaxial MEMS accelerometer was used. This accelerometer is comprised of microscopic movable elements which deflect under the action  
Figure 5: Block diagram of the cart calculation and coordinate correction algorithm. of acceleration in the corresponding direction. The device determines the change in the system's capacitance and, based on that, calculates the deflection of the element and the associated acceleration on a particular axis. The rotation of the device casing results in a change in the direction of standard gravity's action on the accelerometer and, consequently, enables the calculation of the rotation angle. The cant on the curve and on the adjoining straight sections was then measured using a manual track gauge. On the straight sections, the measurements were taken every 10 m. The restored lengths of the curve and ramps are shown in Figure 6. The measurement is marked in blue while the identified linear estimation of the cant variability is in green. It was found that the surveyed layout comprised of two cant transitions and a section with a constant cant value. The cant transitions were not located on transition curves that were not detected on the surveyed geometric layout. An automatic measurement of cant was then taken using the algorithm described above. Measurements were carried out at various velocities of the measuring vehicle. On a properly maintained track, a change in the vehicle velocity had no significant effect on the results of the conducted analyses. An analysis result for the highest of the recorded velocities, i.e., 60 km/h, is shown. A graph of the variability of the recorded acceleration and the restored cant is shown in Figure 7. On straight sections, the estimated cant oscillates around 0, and on the cant transitions (located on the straight sections of the track) an evident increase occurs in the acceleration as well in the calculated cant. At the connection between the straight line and the curve (at the point of tangency which is also a point of the super-elevation ramp end), a rapid change in the direction of acceleration action occurred. After passing this point, the calculated cant value remained at a relatively constant level. An opposite situation occurred at the transition from the curve into the straight line and on the second cant transition. It can be noted that both the restored value of the cant on the curve and the cant variability on the length corresponds to the values measured using the manual track gauge. A mean value of the cant on the circular part of the curve, measured based on the measurement of accelerations, differs by 2 mm (for a velocity of 53 km/h) from the value measured using the track gauge. The oscillation of the restored cant results from the GNSS measurement errors and the induced vibrations of the measuring vehicle itself. The acceleration variability during a passage of the measuring car was then calculated. In order to better illustrate the possibilities offered by the presented methodology, a passage at a velocity of 60 km/h was selected. Figure 8 shows a graph of acceleration variability at the time of running along the curve (only the section between the start of the first cant transitions and the end of the second one is shown). Figure 6: Cant on the curve measured using a manual track gauge. It is evident that this track segment can be divided into five sections characterized by different acceleration variability parameters:  
* Red and blue color--the cant transition located on a straight section.