1. Airport surveillance radar<br /> <br />An airport surveillance radar (ASR) is a radar system used at airports to detect and display the position of aircraft in the terminal area.<br />Digital Airport Surveillance Radar (DASR)<br />The Digital Airport Surveillance Radar (DASR) is a new terminal air traffic control radar system that replaces current analog systems with new digital technologyThe DASR system detects aircraft position and weather conditions in the vicinity of civilian and military airfields. The civilian nomenclature for this radar is the ASR-11. The ASR-11 will replace existing ASR-7, ASR-8, and ASR-9 models. The military nomenclature for the radar is the AN/GPN-30. The older radars, some up to 20 years old, are being replaced to improve reliability, provide additional weather data, reduce maintenance cost, improve performance, and provide digital data to new digital automation systems for presentation on air traffic controller displays. <br /> <br /> [edit] Display systems<br />ASR data is displayed on Automated Radar Terminal System (ARTS), Common Automated Radar Terminal System (CARTS), and Standard Terminal Automation Replacement System (STARS) display consoles in control towers and Terminal Radar Approach Control (TRACON) rooms, usually located at airports. CARTS will be replaced with STARS at all TRACONs during TAMR Phase 3 - Segment 1 as announced by the FAA Federal Aviation Administration in the Spring of 2011. The fate of the remaining ARTS systems will be determined through the FAA's upcoming announcement of TAMR Phase 3 - Segment 2.<br />The Standard Terminal Automation Replacement System (STARS) is a joint Federal Aviation Administration (FAA) and Department of Defense (DoD) program to replace Automated Radar Terminal Systems (ARTS) and other capacity-constrained, older technology systems at 172 FAA and up to 199 DoD terminal radar approach control facilities and associated towers.<br />STARS will be used by controllers, at facilities who already have it installed, to provide air traffic control (ATC) services to aircraft in terminal areas. Typical terminal area ATC services are defined as the area around airports where departing and arriving traffic are served. Functions include aircraft separation, weather advisories, and lower level control of air traffic. The system is designed to accommodate air traffic growth and the introduction of new automation functions which will improve the safety and efficiency.<br /> Airport Surveillance Radar is beginning to be supplemented by ADSB-B Automatic dependent surveillance-broadcast. ADSB-B is a GPS based technology that allows aircraft to transmit their GPS determined position to display systems as quickly as once every second as opposed to once every 4 seconds for a short range radar or once every 13 seconds for an even slower turning long range radar. The FAA is mandating that ADS-B be fully operational. This will allow for older radars to possibly be decommissioned in order to increase safety and also cut costs. <br />