Timeline for Doppler frequency shift radar
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Mar 12, 2017 at 15:42 | vote | accept | Corvinus | ||
| Mar 12, 2017 at 12:55 | answer | added | DJohnM | timeline score: 2 | |
| Mar 12, 2017 at 12:48 | comment | added | diracula | The two possible answers you gave are however the same to first order, so if you neglected second order effects then they are essentially the same answer. (You might try including relativistic effects to see if they then agree.) | |
| Mar 12, 2017 at 12:40 | comment | added | diracula | True, time dilation is a second order effect so you could get the correct first order result by neglecting it. I hadn't considered that, sorry. | |
| Mar 12, 2017 at 12:28 | comment | added | Corvinus | @diracula Yes, you're right. I've edited my question and added that the wave is reflected off the car. As for relativistic effects, I know not taking them into account is going to introduce some error but because $v << c$, I suppose that this effect can be neglected. | |
| Mar 12, 2017 at 12:26 | history | edited | Corvinus | CC BY-SA 3.0 |
added 59 characters in body
|
| Mar 12, 2017 at 12:19 | comment | added | diracula | If the wave is being reflected off the car you should mention it in the question. Also you've added 'without taking into account relativistic effects', but electromagnetic radiation is relativistic so this would give a (significantly) incorrect answer. | |
| Mar 12, 2017 at 12:12 | comment | added | Corvinus | @diracula No. I meant perceived by the radar. The emitted wave is sent how reflects on the car back to the radar. This reflected wave has a different frequency $\omega_r$ than the one that is emitted ($\omega_0$). My question is what is $\omega_r$? | |
| Mar 12, 2017 at 12:10 | history | edited | Corvinus | CC BY-SA 3.0 |
added 51 characters in body
|
| Mar 12, 2017 at 12:08 | comment | added | diracula | Did you mean to instead say 'perceived by the car'? The correct relation is $\omega_r = \left(\frac{1-\beta}{1+\beta}\right)^{\frac{1}{2}} \omega_0$ where $\beta =\frac{v}{c}$ - see here. | |
| Mar 12, 2017 at 10:14 | history | asked | Corvinus | CC BY-SA 3.0 |