مقایسهٔ روش‌ها

	سامانهٔ هشدار برخورد در ترافیک هوایی	انتشار SGP4 TLE
حوزه	هوافضا	هوافضا
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1989	1970s
پدیدآور	FAA, ICAO	NORAD, USAF
نوع	Avionics system	Propagation method
منبع بنیادین	Federal Aviation Administration (2017). Traffic Collision Avoidance System (TCAS II). Technical Standard Order TSO-C119c.	Vallado, D. A., Crawford, P., Hujsa, R., & Kelso, T. S. (2006). Revisiting Spacetrack Report Number 3. In AIAA/AAS Astrodynamics Specialist Conference.
نام‌های دیگر	TCAS II, ACAS, traffic avoidance	SGP4, TLE propagation, simplified perturbations
مرتبط	3	3
خلاصه	TCAS (Traffic Collision Avoidance System) is an airborne safety system that detects nearby aircraft using radar and mode C altitude reports, then provides traffic advisories (TAs) and recommended collision avoidance maneuvers (RAs) to flight crews. Mandated globally on commercial aircraft since 2000, TCAS is considered a last line of defense against mid-air collisions. TCAS II is the most common variant; TCAS I is a simplified advisory-only version for general aviation.	SGP4 (Simplified General Perturbations 4) is a rapid orbital propagation method that predicts satellite position and velocity from Two-Line Element (TLE) sets published by NORAD. Developed in the 1970s, SGP4 accounts for atmospheric drag, gravitational perturbations, and solar radiation pressure using simplified analytical models. SGP4 is the de facto standard for space surveillance, conjunction assessment, and satellite tracking.