The present disclosure provides means for detecting and tracking a moving object using RADAR and ultrasonic sensors. A stationary RADAR detects the moving object and estimates speed and two rotating ultrasonic sensors determine distance of the detected object. An incrementally changing orientation of the ultrasound sensors is associated with an angular speed of rotation based on a last logged distance of the moving object from the ultrasound sensors. Once the moving object is detected, based on an adaptively changing sampling frequency, the moving object is continuously tracked in real time. Conventionally, multiple RADARs are needed for location estimation and motion tracking. Also, merely using a RADAR in combination with an ultrasound sensor also does not serve the purpose since both sensors are static. The present disclosure provides a simple cost effective alternative that can find application in say tracking of an elderly person living alone in an unobtrusive manner.