FACTORS AFFECTING RADAR PROPAGATION

Q11. Q12. Q13. Q14. Q15. Q16. Q17. Q18. Q19. Q20. Q21. Figure 2-14.—Pulse length versus range resolution. REVIEW QUESTIONS How does pulse length affect the amount of energy returned from each pulse? Pulse length is usually measured in what units? What is described by the term "resolution"? What is a radar’s ‘pulse repetition frequency"? What happens when a radar’s PBF is increased? What is meant by the term "range ambiguity"? If a radar had a pulse repetition frequency (PRF) of 1000, what would be its maximum unambiguous range? What causes the phenomena of range folding? How does pulse volume affect radar power? Which beamwidth would provide better target resolution, a large beamwidth or a small beamwidth? What is the effect of beam broadening on radar pulses? Q22. How does the presence of sidelobes affect radar performance? Q23. What is the main cause of degraded azimuthal resolution? Q24. What is the main radar characteristic affecting range resolution? FACTORS AFFECTING RADAR PROPAGATION LEARNING OBJECTIVES: Define refraction and refractive index. Recognize the effects of refractivity on radar systems. Identify effects of subrefraction, superrefraction, and ducting on radar systems. Define and identify effects of diffraction and ground clutter on radar systems. Identify effects of scattering, absorption, and solar activity on radar systems. 2-11