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Answer the questions.

1. What does ”attenuation” mean?

2. What is possible when a very intense area of precipitation is depicted on the radar display?

3. What would be displayed if a second weather cell exists outside of the first?

4. What is the most devastating phenomena that a pilot can encounter?

5. What can these massive systems do?

6. What will pilots do in such situations?

7. What could we suggest to build a hypothetical squall line?

8. What does this type of weather system look like on the radar?

9. Why are controllers very reluctant to accept the responsibility for vectoring aircraft through areas of precipitation?

10. What do controllers do, when the pilots ask them to direct aircraft through areas of precipitation?

Up to this point we have only been discussing primary radar returns (actual reflections from a target), but a controller sees a lot more than raw radar returns on his/her radar display. The total presentation is made up of a combination of real-time information, video map overlays, and processed information that includes some or all of the following items:

• Passive radar reflections or what we have been referring to as primary radar returns. This type of target is only found on surveillance radar systems and is not associated with digital radar equipment. With digital radar, all of the processed information on the radar display would be displayed in a symbolic and graphic format.

• An interchangeable video map overlay which usually depicts obstructions, airports, airspace boundaries, airways and/or navigational aids, and instrument approach courses. A controller has the ability to select from the several maps, including an emergency map which shows highway markings and an exploded view of airports and emergency landing areas.

• Secondary, or active radar returns, which are electronic signals from a transponder and are referred to as beacon replies. The target associated with this signal overlies the pri­mary target return from those aircraft that are equipped with and using a transponder. The resultant target is called a beacon control slash and looks like a longer, slightly fat-in-the-middle, primary return. (This is a good place to mention a very important aspect of active radar returns. In order for this type of target to be displayed, both radar and transpond­er have to be working together. If the transponder is not broadcasting an identifiable reply, it might as well be turned off. This is one reason that we sometimes cannot find an aircraft that is receiving an interrogation signal on its tran­sponder, and it is the most important reason to keep that thing calibrated.) When this beacon control slash is displayed on a radar scope using selected beacon code enhancement features, the target has two slashes. The second of these targets is always in a direct line between the radar antenna and the aircraft and positioned beyond the real target. The space between these slashes will fill in when the controller asks a pilot to ident. This type of system is normally only used when a facility is not equipped with or is not using a numeric or alphanumeric tracking system.

• Numeric or alphanumeric characters which provide information about the aircraft's call sign, speed, and altitude.

There are several other enhancements associated with this system so let's talk a little more about this system.

Most ATC facilities are now equipped with some type of numeric or alphanumeric tracking system that is associated with the transponder or beacon reply, and some even have systems that will track primary targets. In the terminal environment, there is a wide range of equipment sophistication in use depending on the complexity level and needs of the facility and the type of equipment that was in use at the time it was installed. This equipment is constantly being upgraded as technology improves, as FAA funds permit, and as the needs of the facility dictate.

Дата добавления: 2014-11-29