TAILIEUCHUNG - IFF - IDENTIFICATION - FRIEND OR FOE

Originated in WWII for just that purpose - a way for our secondary radars to identify . aircraft from enemy aircraft by assigning a unique identifier code to . aircraft transponders. | IFF - IDENTIFICATION - FRIEND OR FOE Originated in WWII for just that purpose - a way for our secondary radars to identify . aircraft from enemy aircraft by assigning a unique identifier code to . aircraft transponders. The system is considered a secondary radar system since it operates completely differently and independently of the primary radar system that tracks aircraft skin returns only although the same CRT display is frequently used for both. The system was initially intended to distinguish between enemy and friend but has evolved such that the term IFF commonly refers to all modes of operation including civil and foreign aircraft use. There are four major modes of operation currently in use by military aircraft plus one submode. Mode 1 is a nonsecure low cost method used by ships to track aircraft and other ships. Mode 2 is used by aircraft to make carrier controlled approaches to ships during inclement weather. Mode 3 is the standard system also used by commercial aircraft to relay their position to ground controllers throughout the world for air traffic control ATC . Mode 4 is secure encrypted IFF the only true method of determining friend or foe Mode C is the altitude encoder. The non-secure codes are manually set by the pilot but assigned by the air traffic controller. A cross-band beacon is used which simply means that the interrogation pulses are at one frequency and the reply pulses are at a different frequency. 1030 MHz and 1090 MHz is a popular frequency pair used in the . The secondary radar transmits a series of selectable coded pulses. The aircraft transponder receives and decodes the interrogation pulses. If the interrogation code is correct the aircraft transponder transmits a different series of coded pulses as a reply. The advantage of the transponder is that the coded pulses squawked by the aircraft transponders after being interrogated might typically be transmitted at a 10 watt ERP which is much stronger than the microwatt skin

TỪ KHÓA LIÊN QUAN
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.