View Full Version : Calculate origin


Specialist
08-27-03, 12:05 AM
Hi lately I'm been thinking of solving this problem but having no luck.
If 2 stations are place d distance apart in space and they both receive the same transmission t time apart. What would be the formula to calculate the distance the source is from either station 1 or 2?

ei.
*
* Q
*
s1 *
*s2
*

Pretend '*' is the radio wave transmitted. The circle in plance s1, s2 and Q is there sufficient information to calculate Q's position?

cephas1012
08-27-03, 12:57 AM
I dont think you can do it with just two stations. I think you would need a third.

Your equations would look like this:

Sqrt((S1x-Qx)^2+(S1y-Qy)^2)/c=t0
Sqrt((S2x-Qx)^2+(S2y-Qy)^2)/c=t0+t

S1x and S1y is the position of the first station, and S2x and S2y is the position of the second station. I have done this so the waves are all in the same plane. However, In space it would also involve a 3rd dimension.

The first equation is the distance from the source to the 1st station divided by the speed it takes it to get there which equals the time it took (I am assuming we are using light waves here). The second equation is the same thing only replace the first station with the second one. However the time it takes is a little more. That is what the t value represents. t is the difference in the time at which the signal was recieved by each station. Here is the problem. We dont know the value of t0. So we have two equations with 3 unknowns. You could reduce the equations so the position of the source was a function of the time it takes the signal to reach the first station, but you cant find it out exactly.

However, if you included a third station I think it would work out.

There might be another way of doing it so that you could get an answer, but I doubt it. Does this seem right ot everyone else?