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The Radar Method

Let $n_1$ be the integer that labels a pulse emitted by radar unit B. If that pulse gets reflected, or partially reflected, by a scattering event, then let $n_2$ be the integer which the clock assigns to the reflected pulse as it enters the radar receiver. These two integers,

\end{displaymath} (10)

generated by this radar ranging process are the radar coordinates of the scattering event. They assign a unique spacetime location to the scattering event, namely $(t,z)$ as determined by
T_1-Z_1=t-z&\textrm{(pulse moving to the ...
T_2+Z_2=t+z&\textrm{(pulse moving to the left)}
\end{array}\end{displaymath} (11)

Here $(T_1,Z_1)$ and $(T_2,Z_2)$ are those two events at radar unit B which mark the emission and the reception of a pulse at B.


Ulrich Gerlach 2003-02-25