时间：2011-04-18 00:50来源：蓝天飞行翻译 作者：航空 点击：次
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(1)When client or intruder aircraft maneu-ver excessively or abruptly, the tracking algorithm will report incorrect horizontal position until the maneuvering aircraft stabilizes. (2)When a rapidly closing intruder is on a course that crosses the client at a shallow angle (either overtaking or head on) and either aircraft abruptly changes course within . NM, TIS will display the intruder on the opposite side of the client than it actually is. These are relatively rare occurrences and will be corrected in a few radar scans once the course has stabilized. (g)Heading/Course Reference. Not all TIS aircraft installations will have onboard heading reference information. In these installations, aircraft course reference to the TIS display is provided by the Surveillance Systems 4.5.13 Mode S radar. The radar only determines ground track information and has no indication of the client aircraft heading. In these installations, all intruder bearing information is referenced to ground track and does not account for wind correction. Additionally, since ground.based radar will require several scans to determine aircraft course following a course change, a lag in TIS display orientation (intruder aircraft bearing) will occur. As in (f) above, intruder distance and altitude are still usable. (h) Closely.Spaced Intruder Errors. When operating more than 30 NM from the Mode S sensor, TIS forces any intruder within 3/8 NM of the TIS client to appear at the same horizontal position as the client aircraft. Without this feature, TIS could display intruders in a manner confusing to the pilot in critical situations (e.g., a closely.spaced intruder that is actually to the right of the client may appear on the TIS display to the left). At longer distances from the radar, TIS cannot accurately determine relative bearing/distance information on intruder aircraft that are in close proximity to the client. Because TIS uses a ground.based, rotating radar for surveillance information, the accuracy of TIS data is dependent on the distance from the sensor (radar) providing the service. This is much the same phenomenon as experienced with ground.based navigational aids, such as VOR or NDB. As distance from the radar increases, the accuracy of surveillance decreases. Since TIS does not inform the pilot of distance from the Mode S radar, the pilot must assume that any intruder appearing at the same position as the client aircraft may actually be up to 3/8 NM away in any direction. Consistent with the operation of TIS, an alert on the display (regardless of distance from the radar) should stimulate an outside visual scan, intruder acquisition, and traffic avoidance based on outside reference. e. Reports of TIS Malfunctions 1. Users of TIS can render valuable assistance in the early correction of malfunctions by reporting their observations of undesirable performance. Reporters should identify the time of observation, location, type and identity of aircraft, and describe the condition observed; the type of transponder processor, and software in use can also be useful information. Since TIS performance is monitored by maintenance personnel rather than ATC, it is suggested that malfunctions be reported in the following ways: (a)By radio or telephone to the nearest Flight Service Station (FSS) facility. (b)By FAA Form 8740.5, Safety Improve-ment Report, a postage.paid card designed for this purpose. These cards may be obtained at FAA FSSs, General Aviation District Offices, Flight Standards District Offices, and General Aviation Fixed Based Operations. 4.5.7. Automatic Dependent Surveillance.Broadcast (ADS.B) Services a. Introduction 1.Automatic Dependent Surveillance.Broad-cast (ADS.B) is a surveillance technology being deployed in selected areas of the NAS (see FIG 4.5.7). ADS.B broadcasts a radio transmission approximately once per second containing the aircraft’s position, velocity, identification, and other information. ADS.B can also receive reports from other suitably equipped aircraft within reception range. Additionally, these broadcasts can be received by Ground Based Transceivers (GBTs) and used to provide surveillance services, along with fleet operator monitoring of aircraft. No ground infrastruc-ture is necessary for ADS.B equipped aircraft to detect each other. 2.In the U.S., two different data links have been adopted for use with ADS.B: 1090 MHz Extended Squitter (1090 ES) and the Universal Access Transceiver (UAT). The 1090 ES link is intended for aircraft that primarily operate at FL 180 and above, whereas the UAT link is intended for use by aircraft that primarily operate at 18,000 feet and below. From a pilot’s standpoint, the two links operate similarly and support ADS.B and Traffic Information Service.Broadcast (TIS.B), see paragraph 4.5.8. The UAT link additionally supports Flight Information Services.Broadcast (FIS.B), subpara-graph 7.1.11d. 4.5.14 Surveillance Systems FIG 4.5.7 ADS.B, TIS.B, and FIS.B: Broadcast Services Architecture b. ADS.B Certification and Performance Requirements ADS.B equipment may be certified as an air.to.air system for enhancing situational awareness and as a surveillance source for air traffic services. Refer to the aircraft’s flight manual supplement for the specific aircraft installation. c. ADS.B Capabilities 1. ADS.B enables improved surveillance ser-vices, both air.to.air and air.to.ground, especially in areas where radar is ineffective due to terrain or where it is impractical or cost prohibitive. Initial NAS applications of air.to.air ADS.B are for “advisory,” use only, enhancing a pilot’s visual acquisition of other nearby equipped aircraft either when airborne or on the airport surface. Additionally, ADS.B will enable ATC and fleet operators to monitor aircraft throughout the available ground station coverage area. Other applications of ADS.B may include enhanced search and rescue operations and advanced air.to.air applications such as spacing, sequencing, and merging. 2. ADS.B avionics typically allow pilots to enter the aircraft’s call sign and Air Traffic Control (ATC).assigned transponder code, which will be transmitted to other aircraft and ground receivers. Pilots are cautioned to use care when selecting and entering the aircraft’s identification and transponder code. Some ADS.B avionics panels are not interconnected to the transponder. Therefore, it is extremely important to ensure that the transpond-er code is identical in the ADS.B and transponder panel. Additionally, UAT systems provide a VFR “privacy” mode switch position that may be used by pilots when not wanting to receive air traffic services. This feature will broadcast a “VFR” ID to other aircraft and ground receivers, similar to the “1200” transponder code. |
