Electrical pulses with independent and identically distributed random ampli- tudes ξ1,ξ2,... arrive at a detector at random times W1,W2,... according to a Poisson process of rate λ. The detector output θk(t) for the kth pulse at time t is 0 for t < Wk, θk(t)= ξkexp{−α(t−Wk)} That is, the amplitude impressed on the detector when the pulse arrives is ξk, and its effect thereafter decays exponentially at rate α. Assume that the detector is additive, so that if N(t) pulses arrive during the time interval [0,t], then the output at time t is: