Some Properties of the Output of an Integrator in an Infrared System

An analysis of the output of a running integrator in an infrared scanner model is presented. The sensor is corrupted by thermal noise, generation-recombination noise, photon noise, and modulation noise. Expressions for the signal voltage density spectrum, signal pulse shape, noise power spectrum, and average noise power at the integrator output are derived. A graphical description of the signal-to-noise ratio (SNR) at the integrator output versus time is included, and a comparison of the integrator SNR with that of a matched filter is provided. Expressions are given for the signal pulse shape and the average noise power when the integration time is subject to small Gaussian errors.