Subelement A: RADAR Principles – 10 Key Topics – 10 Exam Questions – 8 Drawings— Topic 2: Distance and Time
Question 8-2A3
Element 8 (RADAR)RADAR range is measured by the constant:
Explanation
RADAR measures range by sending out a radio pulse and timing how long it takes for the echo to return. Radio waves travel at approximately the speed of light, which is $3 \times 10^8$ meters per second. This means in one microsecond ($10^{-6}$ seconds), a radio wave travels 300 meters.
Since the RADAR measures the *total round trip* time (out to the target and back), the actual one-way distance to the target is half of the total distance traveled by the pulse. Therefore, for every microsecond of elapsed time, the target is 300 meters / 2 = 150 meters away. This is a fundamental constant used in RADAR calculations.
Options B and C are incorrect because they use "yards" instead of "meters," and C represents the total round-trip distance, not the one-way range. Option D is an incorrect value and unit combination for this calculation.
Related Questions
8-2A1 A radio wave will travel a distance of three nautical miles in:8-2A2 One RADAR mile is how many microseconds?8-2A4 If a target is 5 miles away, how long does it take for the RADAR echo to be received back at the antenna?8-2A5 How long would it take for a RADAR pulse to travel to a target 10 nautical miles away and return to the RADAR receiver?8-2A6 What is the distance in nautical miles to a target if it takes 308.5 microseconds for the RADAR pulse to travel from the RADAR antenna to the target and back.