Skip to main content
MathOverflow

You are not logged in. Your edit will be placed in a queue until it is peer reviewed.

We welcome edits that make the post easier to understand and more valuable for readers. Because community members review edits, please try to make the post substantially better than how you found it, for example, by fixing grammar or adding additional resources and hyperlinks.

3
  • 26
    $\begingroup$ To elaborate on this, because it's more applied than the rest: Many radar systems work by sending EM pulses out at regular intervals, waiting in between pulses to look for reflections from objects. You want to calculate an object's distance from the time it takes to see a reflection. If time between pulses is very long, this works, but if you're observing something dynamic you want fast updates, so you need shorter time between pulses. But then you don't know which pulse's reflection you're seeing, so object range is only known modulo (speed of light)*(pulse interval). (cont'd) $\endgroup$ Commented Jul 30, 2010 at 2:14
  • 14
    $\begingroup$ (cont'd from above) The solution is to send out a few different types of pulses (say, with different wavelengths of light), with each type of pulse having it's own pulse interval, and making those intervals coprime. Then you can use the CRT to calculate range mod some very large distance (where you know, practically speaking, that you won't be registering any reflections from such large distances). $\endgroup$ Commented Jul 30, 2010 at 2:23
  • 7
    $\begingroup$ This is detailed on p 306 of Roger Sullivan's book Microwave radar: imaging and advanced concepts $\endgroup$ Commented Oct 16, 2010 at 2:10