Abstract: A data acquisition system employs data conversion circuitry well suited to large multisensor systems such as computerized tomography systems utilizing X-ray detectors. The data conversion system consists of a number of detectors or similar signal sources and a corresponding number of data registers and accumulation registers. Each data register contains a previous sample output of a signal source. Differential data conversion is employed such that the difference between the previous output and the current signal source output is added to the data register in order to update it to the current signal source output. Each signal source is repeatedly sampled and the samples accumulated in an accumulation register. The data conversion system thus provides increased system linearity, accuracy, and dynamic range, and yields improved measurement simultaneity of a large number of signal sources. These factors combine to result in substantial improvement in image resolution after suitable processing by a computer.

Abstract: In portable seismic data acquisition units, an adaptive seismic signal processor and method for resampling and bandpassing selected frequencies of an input digital signal. The adaptive seismic signal processor and method provide an output digital signal having a frequency domain and resampling rate which can be selected from one of a plurality of predetermined frequency domains and sampling rates during the course of acquisition of the input digital signal without substantial loss or deterioration thereof.