English Chinese translation sample-Federal Aviation Administration

（Traslated by freelance Chinese translator li – English to Chinese translation or Chinese to English translation services）

Unlike radar, ADS-B accuracy does not seriously degrade with range, atmospheric conditions, or target altitude, and update intervals do not depend on the rotational speed or reliability of mechanical antennas. When a Radar measures the bearing, it is done by the position of the rotating radar antenna when it receives a reply to its interrogation from the aircraft, and it measures the range by the time it takes for the radar to receive the reply. The beam of the antenna gets wider as the aircraft get farther from the antenna, thus making the measured position information less accurate. An ADS-B based system, on the other hand, would listen for position reports broadcast by the aircraft. These position reports are based on accurate navigation systems, such as GPS. The accuracy of the system is not affected by measurement errors, and is unaffected by the range to the aircraft.

With the radar, detecting aircraft velocity changes requires tracking the received data and can only be detected over a period of several position updates. With ADS-B, velocity changes are broadcast almost instantaneously as part of the State Vector report.

ADS-B can decrease the number of active interrogations required by ACAS, thus increasing effective range in high density airspace.

It will also reducing unnecessary alarm rate by incorporating the ADS-B state vector, aircraft intent, and other information.

It extends collision avoidance below 1000 feet above ground level, and detecting runway incursions.

Eventually, the ACAS function may be provided based solely on ADS-B, without requiring active interrogations of other aircraft transponders

These improvements in surveillance accuracy can increase airport and airspace capacity while also improving safety.

ADS-B is also a relatively inexpensive technology. Also, unlike radar, both the footprint and power requirements for ADS-B are quite small, allowing an ADS-B ground station to be installed in even the most remote areas.

与传统雷达不同，ADS-B（广播式自动相关监视）的精确性不随着范围、大气条件和目标高度等因素的变化而明显降低，而且更新间隔也不依赖于转动速度或者天线的可靠性。雷达是通过转动天线接收到航空器反馈信号时的位置来测定目标方位，通过测量接收反馈信号的时间来计算距离。航空器距离雷达越远，天线发射的电波就越发散，因此所测量的方位信息就越不准确。基于ADS-B的系统则不同，它将接收航空器发送的方位报告。这些方位报告是基于精确的导航系统而形成的，比如GPS。因此ADS-B的精确性不受测量误差的影响，也不受航空器距离远近的影响。

雷达在侦测航空器速度变化时，需要跟踪记录所接收的反馈数据，而且需要经过一段数次方位数据更新的时间。采用ADS-B，速度变化信息作为状态向量报告的一部分几乎是即时发报的。

ADS-B能够降低ACAS（机载防撞系统）所要求的电波发射次数，因此在高密度空域中可以扩大有效覆盖范围。

通过综合运用状态矢量、航空器意图等信息，ADS-B还能够降低不必要警报的发送频率。

它能够在距地面1000英尺以下的空域内防止空中相撞，还能监测到飞机跑道入侵。

最后，ADS-B很可能单独提供ACAS的功能，而不需要其他的机载雷达收发机发送信号。

这些监视精确性方面的进步，能够提高机场和空域的管制能力，同时增强安全性。

ADS-B同时还是一种相对廉价的技术。而且与雷达不同，对覆盖区域和动力要求都非常低，因此即便是在最偏远的地区也可以建立ADS-B地面站。