雷達與聲納物理學：飛行時間與雙脈衝法
Welcome to Billy Sir’s Interactive Physics Masterclass. In this interactive guide, we will explore how modern technology uses waves to measure distance and speed. Whether it is a police radar gun using Electromagnetic (EM) waves or a submarine using Sound waves (Sonar), the underlying physics remains the same.
歡迎來到 Billy Sir 的互動物理大師課。在這個互動指南中，我們將探討現代科技如何利用波來測量距離和速度。無論是使用電磁波的警察雷達槍，還是使用聲波的潛艇聲納，其背後的物理原理都是相同的。
How do we measure distance? (Time-of-Flight)
By sending a pulse of energy and timing how long it takes for the echo to return, we can calculate the exact distance to a target using the formula: Distance = (Wave Speed × Time) / 2.
我們如何測量距離？（飛行時間測距）
通過發射能量脈衝並計算回聲返回所需的時間，我們可以使用公式：距離 = (波速 × 時間) / 2 來計算目標的精確距離。
Radar & Sonar Masterclass
雷達與聲納大師課
Billy Sir's Interactive Physics: Time-of-Flight & Two-Pulse Method.
物理化學 Billy Sir 互動物理：飛行時間測距與雙脈衝測速
1. Finding Distance (Time of Flight) 測量距離 (飛行時間)
The device sends out a short burst of energy and starts a timer. When the pulse hits the target, it bounces back. The device stops the timer when it hears the echo. 設備發出短促的能量脈衝並啟動計時器。當脈衝擊中目標時會反彈。設備在接收到回聲時停止計時。
2. Finding Speed (Two-Pulse Method) 測量速度 (雙脈衝法)
The device measures the distance once (\(d_1\)), waits a tiny fraction of a second (\(\Delta t\)), and measures the distance again (\(d_2\)). The difference in distance over time gives the speed. 設備測量一次距離 (\(d_1\))，等待極短的時間 (\(\Delta t\))，然後再次測量距離 (\(d_2\))。距離差除以時間即為速度。
How do we measure speed? (Two-Pulse Method)
To find how fast an object is moving, the device sends out two consecutive pulses separated by a tiny time gap (Δt). By comparing the change in distance between the two pulses, we can calculate the target’s speed.
我們如何測量速度？（雙脈衝法）
為了找出物體的移動速度，設備會發出兩個連續的脈衝，中間相隔極短的時間 (Δt)。通過比較這兩個脈衝之間的距離變化，我們可以計算出目標的速度。