The aim of this paper is to evaluate real-time accurateness of low-altitude height measurement using a single sonar sensor via Kalman filter algorithm in embedded controller. The function of the one dimension embedded Kalman filter of sonar sensor is to reduce and resolve the error of low altitude height measurement that produced from the sensor for mapping application. Series data of varied height measurement with Kalman filter was gathered and implemented using a 16-bit microcontroller unit. A structure model was constructed to allow for dynamic height measurement between ground surface and the sensor.The tabulated data are shown for comparison of accuracy and error analysis between both with Kalman and without Kalman filter. After several scanned surfaces and analysis of the recorded data, the technique shows the usefulness in height measurement application that used surface scan method which the sonar project to the ground such as UAV in order to reduce error of the detected varied height.