1-22. Which of the following radar reference  coordinates  is  the  plane in which all angles in the up direction  are  measured? 1. Horizontal  plane 2. Vertical plane 3.   Los 4. Elevation  angle 1-23. Which of the following radar reference  coordinates  is  the  angle between the horizontal plane and LOS? 1. Relative bearing 2. Azimuth  angle 3. Elevation  angle 4. True bearing 1-24. Which of the following factors will effect range performance if the leading edge of the rf pulse is sloping? 1. An increased pulse width 2. Lack of definite point of measurement for elapsed time on  the  indicator  time  base 3. A weaker return echo 4. A decrease in frequency 1-25. Which of the following antenna characteristics  will  provide greater  range  capability? 1. Higher antenna 2. Wider beam width 3. Faster rotation 4. Electronic scanning 1-26. A radar’s ability to detect bearing is determined by which of the  following  characteristics? 1. Transmit power out 2. Echo signal strength 3. Receiver sensitivity 4. All of the above 1-27. Which of the following systems are positioned to the point of maximum signal  return? 1. Weapons control and surface search 2. Surface  search  and  guidance 3. Guidance  and  weapons  control 4. Guidance and navigation 1-28. The refraction index of the lowest few-hundred  feet  of  atmosphere will cause a ducting affect on radar waves. Ducting  may  cause which  of  the  following  results? 1. Increased  bending  of  radar waves 2. Extended radar horizon 3. Reduced radar horizon 4. All of the above 1-29. When using a high-frequency radar during a heavy rain storm, you should expect which of the following  results? 1. Minimum range will increase 2. Usable  range  will  be  reduced 3. Range  resolution  will  decrease 4. Range ability will NOT change 1-30. Using  table  1-1,  classify  the AN/GPN-27. 1. Fixed radar for detecting and searching 2. Portable sound in air for fire control  or  searchlight directing 3. Mobile radar for detecting and searching 4. General radar for navigation 1-31. Which of the following types of radars would be used to track an aircraft  over  land? 1. Surface search radar 2. Fire control tracking radar 3. Air search radar 4. Height-finding radar 3