Relativistic Radar Signal Return Time This animation shows the motion of both the space ship (at speed v) and the radar pulse (speed c) that is emitted from the ship and is reflected from a distant stationary object and then received by the ship. The goal of any radar is to compute the time interval between pulse emission and reception. Since the speed of the ship can be substantial fraction of the speed of the pulse, c, that speed has a significant effect in reducing the time interval. If the range at pulse emission is r then the time interval for the pulse to get to the object is dtOut=r/c. The time for the pulse to get back to the moving ship has to be computed from the following equation: dtRefl=(r-v(dtOut+dtRefl))/c then solving for dtRefl we get: dtRefl=(r(1-v/c))/c and the total time interval becomes the sum: dtSum=r/c+r(1-v/c)/(c+v)=2r/(c+v) This expression is used to compute the "Expected Time Interval" that is written on the page after the pulse is received.
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beta range Single Step