The report describes the development of information processing circuitry for the all-electronic infrared horizon scanner. Two different information processing schemes are described Video pulse switching and modulated carrier gating. In the video pulse switching scheme, pitch and roll attitude error signals are derived by proper processing of the vidicon tubes video pulse output. In the modulated carrier gating method, pitch and roll attitude error signals are derived by using the vidicon tubes video pulse output as a gating pulse, gating deflection voltage ramp signals which are further processed to obtain output error signals. The relative merits of each scheme are discussed in terms of circuit simplicity and reliability.