Subelement E: Antenna Systems- 5 Key Topics – 5 Exam Questions— Topic 39: Antenna Systems
Question 8-39E3
Element 8 (RADAR)Good bearing resolution largely depends upon:
Explanation
Good bearing resolution, in the context of direction finding or accurately determining the horizontal angle to a signal source, relies on the antenna's ability to discriminate between signals arriving from closely spaced directions.
A **narrow antenna beam in the horizontal plane** (azimuth) provides high directivity. This means the antenna is highly sensitive to signals coming from a very specific horizontal angle and much less sensitive to signals from other angles. When you rotate such an antenna, the signal strength will peak sharply when the antenna points directly at the source, allowing for a precise determination of the signal's bearing.
Conversely:
* **A high transmitter output reading** (A) relates to the power of the outgoing signal, affecting range or signal strength, not the precision of determining direction.
* **A high duty cycle** (B) refers to the proportion of time a transmitter is active, which impacts average power and heating, but not directional resolution.
* **A narrow antenna beam in the vertical plane** (C) helps with determining elevation angle or reducing ground reflections, but bearing is a horizontal measurement.
Related Questions
8-39E1 Slotted waveguide arrays, when fed from one end exhibit:8-39E2 A typical shipboard RADAR antenna is a:8-39E4 The center of the transmitted lobe from a slotted waveguide array is:8-39E5 How does antenna length affect the horizontal beamwidth of the transmitted signal?8-39E6 What is the most common type of RADAR antenna used aboard commercial maritime vessels?