President Trump discussed renovations to the reflecting pool near the Lincoln Memorial during an event on health care on Thursday.Credit...Eric Lee for The New York Times
Trump Says He’s Renovating ‘Filthy’ Reflecting Pool on the National Mall
The pool, which is more than 2,000 feet long, was the site of Martin Luther King Jr.’s “I Have a Dream” speech and other events.
Communication Failures Preceded Deadly Crash at LaGuardia, N.T.S.B. Says
The report focuses on the lack of transponders in the fire trucks, which investigators suggested could have allowed an automatic warning system to alert the controller of an imminent collision.
應答器
/trɑːn(t)ˈspɒndə/
應答器 - Flight First 應答器是一種電子設備,當接收到特定的詢問訊號時,它會自動接收、放大並重新發送訊號(或發出新的訊號)。應答器是「發射器」(transmitter)和「應答器」(responder)的組合詞,這些設備對於航空、衛星技術和安全系統中的識別、通訊和位置追蹤至關重要。
主動式與被動式:主動式轉發器需要電源才能發送訊號,而被動式轉發器(例如 RFID 標籤)則由接收到的訊號供電。
Moonraker Online
transponder
/trɑːn(t)ˈspɒndə/
A transponder is an electronic device that automatically receives, amplifies, and retransmits a signal (or emits a new one) upon receiving a specific interrogation signal. A blend of "transmitter" and "responder," these devices are critical for identification, communication, and location tracking in aviation, satellite technology, and security systems.
Key Applications and Uses
Aviation (ATC): Aircraft transponders send a 4-digit squawk code and altitude data to Air Traffic Control (ATC) radar, identifying the aircraft and enhancing safety.
Satellites: Communications satellites use transponders to receive signals from Earth, change their frequency, and retransmit them back.
Everyday Technology: Used in passive keyless entry systems for cars, automated toll collection (e.g., E-ZPass), and RFID tags for tracking race participants.
Fiber Optics: Transponders convert short-range optical signals into long-range signals for network communication.
Common Transponder Types & Modes
Mode Alpha (A): Transmits a 4-digit identification code.
Mode Charlie (C): Transmits identification and pressure altitude.
Mode Sierra (S): Offers advanced capabilities, transmitting identification, altitude, speed, and registration details.
Differences from Other Devices
Transponder vs. Transceiver: A transponder sends a signal only when it receives one, whereas a transceiver is a transmitter and receiver combined, used for continuous communication.
Active vs. Passive: Active transponders need power to send a signal, while passive transponders (like RFID tags) are powered by the incoming signal.