AIM
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the entire flight. Assignments are made by the ARTCC computer on the basis of the National Beacon Code
Allocation Plan. The equipment is also designed to receive Mode C altitude information from the aircraft.
d.
It should be emphasized that aircraft transponders greatly improve the effectiveness of radar systems.
REFERENCE
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AIM, Para 4
20, Transponder and ADS
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B Out Operation.
4
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5
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3. Surveillance Radar
a.
Surveillance radars are divided into two general categories: Airport Surveillance Radar (ASR) and Air
Route Surveillance Radar (ARSR).
1.
ASR is designed to provide relatively short
−
range coverage in the general vicinity of an airport and to
serve as an expeditious means of handling terminal area traffic through observation of precise aircraft locations
on a radarscope. The ASR can also be used as an instrument approach aid.
2.
ARSR is a long
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range radar system designed primarily to provide a display of aircraft locations over
large areas.
b.
Surveillance radars scan through 360 degrees of azimuth and present target information on a radar display
located in a tower or center. This information is used independently or in conjunction with other navigational
aids in the control of air traffic.
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5
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4. Precision Approach Radar (PAR)
a.
PAR is designed for use as a landing aid rather than an aid for sequencing and spacing aircraft. PAR
equipment may be used as a primary landing aid (See Chapter 5, Air Traffic Procedures, for additional
information), or it may be used to monitor other types of approaches. It is designed to display range, azimuth,
and elevation information.
b.
Two antennas are used in the PAR array, one scanning a vertical plane, and the other scanning horizontally.
Since the range is limited to 10 miles, azimuth to 20 degrees, and elevation to 7 degrees, only the final approach
area is covered. Each scope is divided into two parts. The upper half presents altitude and distance information,
and the lower half presents azimuth and distance.
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5
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5. Airport Surface Detection Equipment (ASDE
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X)/Airport Surface Surveillance
Capability (ASSC)
a.
ASDE
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X/ASSC is a multi
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sensor surface surveillance system the FAA is acquiring for airports in the
United States. This system provides high resolution, short
−
range, clutter free surveillance information about
aircraft and vehicles, both moving and fixed, located on or near the surface of the airport’s runways and taxiways
under all weather and visibility conditions. The system consists of:
1. A Primary Radar System.
ASDE
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X/ASSC system coverage includes the airport surface and the
airspace up to 200 feet above the surface. Typically located on the control tower or other strategic location on
the airport, the Primary Radar antenna is able to detect and display aircraft that are not equipped with or have
malfunctioning transponders or ADS
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B.
2. Interfaces.
ASDE
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X/ASSC contains an automation interface for flight identification via all automation
platforms and interfaces with the terminal radar for position information.
3. Automation.
A Multi
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sensor Data Processor (MSDP) combines all sensor reports into a single target
which is displayed to the air traffic controller.
4. Air Traffic Control Tower Display.
A high resolution, color monitor in the control tower cab provides
controllers with a seamless picture of airport operations on the airport surface.
b.
The combination of data collected from the multiple sensors ensures that the most accurate information
about aircraft location is received in the tower, thereby increasing surface safety and efficiency.
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5
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4
Surveillance Systems