Final answer:
Radar technology measures distance by using the time it takes for radio waves to travel to an object and back, known as echo time.
Radar has been used to determine the distance to Venus and can measure the speed and location of objects such as cars and airplanes with high precision.
The Correct Option ; d) LIDAR
Step-by-step explanation:
The principle that distance can be measured by computing the time required for reflected energy to be measured at the source is the basis of radar technology. Radar uses radio waves to detect the location and speed of distant objects by transmitting waves to a target and then receiving the waves that are reflected back.
The time it takes for the waves to return is called the echo time. This time, when multiplied by the speed of light, gives the total distance traveled by the waves, which is then halved to find the distance to the object since the waves travel to the object and then back to the radar equipment.
Radar astronomy has been pivotal in our understanding of the solar system's dimensions. It was first used to measure the distance to Venus accurately.
By knowing that radio waves travel at the speed of light, and measuring the round-trip time of these waves, the distance to Venus or any other object can be determined with great precision.
For practical examples, if the echo time for Venus is 1000 seconds, this means that light traveled to Venus and back in that time period.
For a highway police radar unit to detect a car at a distance of 75.0 meters, the wave would travel 150 meters round-trip, and the corresponding echo time would be the time taken for radio waves to cover that distance at the speed of light. To determine the distance to an airplane 12.0 kilometers away within a precision of 10.0 meters, the echo time must be measured with an accuracy within the range of nanoseconds.