Multiple choice

Which of the following modulation techniques is used specifically in instrument landing systems?

  1. AM

  2. FM

  3. PM

  4. SM

  5. QAM

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Space modulation is a radio amplitude modulation technique used in instrument landing systems that incorporates the use of multiple antennas fed with various radio frequency powers and phases to create different depths of modulation within various volumes of three-dimensional airspace.