Can doppler effect be used to identify the direction of the moving object

[kjfunh]

I read some articles about Doppler effect today and found them very helpful.But, except for just recognizing if the object is moving away or toward us, can we identify the direction (as vector) of the moving object

[studiot]

Yes and no.

 

A single observer cannot do this, from the doppler effect.

For example there is no doppler effect for motion at right angles to the line of intersection or for two bodies that are not moving apart.

 

The size of the doppler shift gives you a value of the relative velocity along a vector which is the common line of intersection.

 

So if you have another observer (In 2D) or two more observers (in3D) you can use the three such lines to find the resultant velocity of the object.

 

However the observers must be suitably placed to achieve any accuracy.

[Enthalpy]

Several observers or several sources of sound that the target reflects. This is done to know the position of a submarine from the reflection of the noise created at the Ocean's surface. The hunter measures the surface noise over many directions and correlates it with the directions at depth; reflections, if any, reveal the target. The signal processing includes Doppler measure and compensation, and this indicates the target's 3D speed in addition to its position.

 

You guessed:submarines are built to reflect as little noise as possible, and they hide in terrains that reflect noise, preferably behind mountains.

[kjfunh]

Thanks

[studiot]

It should be noted that this is not the method used for doppler satellite positioning.