AIM 8/15/19  1/30/20 4 − 5 − 5. Airport Surface Detection Equipment (ASDE − X)/Airport Surface Surveillance Capability (ASSC) 4 − 5 − 3. Surveillance Radar 4 − 5 − 4. Precision Approach Radar (PAR) 4 − 5 − 7 Surveillance Systems 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 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. 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. 3. Automation. A Multi − sensor Data Proces- sor (MSDP) combines all sensor reports into a single target which is displayed to the air traffic controller. 2. Interfaces. ASDE − X/ASSC contains an automation interface for flight identification via all automation platforms and interfaces with the terminal radar for position information. 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. 3. Center Radar Automated Radar Terminal Systems (ARTS) Processing (CENRAP) was devel- oped to provide an alternative to a nonradar environment at terminal facilities should an ASR fail or malfunction. CENRAP sends aircraft radar beacon target information to the ASR terminal facility equipped with ARTS. Procedures used for the separation of aircraft may increase under certain conditions when a facility is utilizing CENRAP because radar target information updates at a slower rate than the normal ASR radar. Radar services for VFR aircraft are also limited during CENRAP operations because of the additional workload required to provide services to IFR aircraft. 1. A Primary Radar System. ASDE − X/ ASSC system coverage includes the airport surface and the airspace up to 200 feet above the surface. T ypically 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 transpon- ders or ADS − B. a. ASDE − X/ASSC is a multi − 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: 2. ARSR is a long − range radar system designed primarily to provide a display of aircraft locations over large areas. 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. 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. a. Surveillance radars are divided into two general categories: Airport Surveillance Radar (ASR) and Air Route Surveillance Radar (ARSR).