Sensors, devices, systems, devices, and methods for providing wireless modular self-contained units with battery power supply that can use radar, ultrasonic, and IR measuring techniques and sensors for directional detection of impeding objects, persons, or moving targets, and can be used with mobile smart phones and the like. The modular sensor units can be used as a displacement and motion measurement sensor for point of reference measurement applications. The displacement sensing method can use radar, ultrasonic, and IR measuring techniques for directional detection of impeding objects, persons, or moving targets. Upon the detection of the said target, algorithms make use of the direction, angle of ascent, and speed to provide real time position data represented in discrete format. The said sensors are modular in embodiment allowing for multiple sensors to be positioned in strategic regions on the person or system of interest to study the said frame using the method of moments to dissect the object in varying degrees of granularity. The sensor shall connect wirelessly to a mobile handheld (i.e. the end user's smartphone) device for real-time data acquisition along with seamless integration into an existing IMU only based system requiring information beyond six degrees of freedom as normally represented by gyros, and accelerometers.