There are lots of explanation related to the ping sonar, range, distance sensor, ultrasonic distance, and distance are described inside this datasheet. The datasheet presents info like measurement, ping sensor, ultrasonic, and pulse width.
In the datasheet the reader can read things around pulse, ultrasonic distance sensor, microcontroller, sensor, and ping. These are some excerpt from the datasheet:
The Parallax PING))) ultrasonic distance sensor provides precise, non-contact distance measurements from about 3 cm (1.2 inches) to 3 meters (3.3 yards). It is very easy to connect to BASIC Stamp® or Javelin Stamp microcontrollers, requiring only one I/O pin. The PING))) sensor works by transmitting an ultrasonic (well above human hearing range) burst and providing an output pulse that corresponds to the time required for the burst echo to return to the sensor. By measuring the echo pulse width the distance to target can easily be calculated. Features • • • • • • • • • • Supply Voltage – 5 VDC Supply Current – 30 mA typ; 35 mA max Range – 3 cm to 3 m (1.2 in to 3.3 yrds) Input Trigger – positive TTL pulse, 2 uS min, 5 µs typ. Echo Pulse – positive TTL pulse, 115 uS to 18.5 ms Echo Hold-off – 750 µs from fall of Trigger pulse Burst Frequency
Giving more content, the datasheet tells the reader discussion things like sonar sensor, the echo pulse, conversion factors, and the ping sensor.