时间:2011-08-27 23:38来源:蓝天飞行翻译 作者:航空 点击:次
See also Interrogation Side Lobe Suppression. Side Lobes (Antenna) Lobes of the radiation pattern of an antenna, which are not part of the main or principal beam. Radar systems can have sufficient sensitivity via side lobes for successful detection of aircraft (particularly for SSR, but also for PSR). Special precautions are necessary to protect against these false plots. SIGMET Information Information issued by a meteorological watch office concerning the occurrence or expected occurrence of specified en-route weather phenomena which affect the safety of aircraft operations. Signal-Derived Position Error That part of the horizontal position error at the user location attributable to signal-in-space errors from the GNSS control segment, space segment and propagation effects; does not include receiver-induced errors. Signal-Derived Range Accuracy Measured pseudorange error on a particular satellite as observed by a ground monitor station. SRA includes the signal of the error. Signal-to-Noise Ratio A ratio of magnitude of a desired signal to the magnitude of the noise received with it. Significant Point A specified geographical location used in defining an ATS route or the flight path of an aircraft and for other navigation and ATS purposes. Significant Repositioning A repositioning of a sequenced aircraft that involves more than an accepted (parameter) number of changes. Silent Co-ordination See Active Mode of Real-Time Civil/Military Co-ordination. Simulation Conducting dynamic experiments on a model instead of on the real system. |