The received signal is the sum of the direct and ground-reflected signals and since they travel at different distances they have different time delays. If the transmitted signal is s(t) then the received signal is x t s t t s t t ( ) ( ) ( ) = − + − 1 2 The amount of delay (in seconds) can be computed for both propagation paths, using the fact that the time delay is the distance divided by the speed of light (3 10 × 8 m/sec). Determine t1 and t2 as a function of d1.