The algorithm of optimal radiometric signal processing in microwave radiometer with the unstable transfer characteristic of an entrance path and an adjustable source of a reference signal in the assumption that the entrance path of radiometer consist of an operated switch, an adjustable source of a reference signal and the generator of modulating signal is synthesised and is executed in the form of an entrance part of Dicke receiver. It is shown that the optimal algorithm contains operations of decorrelation of supervision, square-law and synchronous (with modulating function) detecting. Estimation of the signal parameter is accepted from the adjustable source during time moments when the radiometer exit is equal to zero. The block diagramme of optimal algorithm is offered. Theoretically limiting accuracy of measurements is calculated.
zero-type radiometer, optimal algorithm, potential accuracy of estimation