Abstract :
An ocean acoustic data acquisition and processing system is discussed. The system is based on the Aptec Computer Systems 2400 I/O Computer (IOC) and is controlled by a DEC VAX 11/730 minicomputer running the VMS operating system.The system utilizes a High Density Digital Recorder (HDDR), an FPS 5205 Array Processor, a number of fixed disks, a Lexidata color display, a QMS laser printer, and a 9-track tape unit.Real-time processing performed with the system includes 1) the collection of HDDR time series data, 2) the computation and storage of selected time-to-frequency FFT bins, cross-spectral matrices,and FFT-beamformer outputs, 3) the plotting of hydrophone power vs. time, and signal power vs. frequency and azimuth, and 4) the backing up of processed data and maintenance of logs of the data. The VAX remains relatively free to perform other concurrent tasks since the Aptec system handles items 1 and 2 above. Data rates used are 16 channels at 1500 Hz, and 128 channels at 699 Hz.
