Inertial Navigation Systems (INS) are critical for a wide range of applications due to their ability to provide reliable navigation information, even without external references. This paper presents a comprehensive study of the modeling of low-cost INS sensors and their inherent errors, focusing on how these errors impact the accuracy of the system's localization outputs. A MATLAB-based simulation platform was developed to analyze the effects of common sensor errors on position, velocity, and attitude over time. The experimental results show that these errors accumulate, leading to significant deviations from the true trajectory. Notably, the maximum positional error in the upward direction reached 65 meters by the end of the simulated trajectory, while the velocity error in the same direction deviated by 0.8 m/s. Initially, the estimated trajectory closely followed the reference path, but as the simulation progressed, a substantial divergence occurred, highlighting the cumulative impact of sensor errors. These findings underscore the necessity of advanced error mitigation techniques to enhance the long-term accuracy and reliability of INS in practical applications.