Abstract: A method is provided to process system test data to determine certification parameters of the system based on the test data. For a torpedo launch system, the velocity data is generated by a Pressure/Velocity/Displacement housing interfaced with a computer based data acquisition system and known launch system and test parameters, such as sample rate, muzzle exit length, time of acquisition, decimation factor and low pass cutoff frequency are provided as inputs. The method forces assigns a value of zero to any data less than a predetermined threshold in order to eliminate non-zero levels contributed by ambient noise. The method then passes the data through a filter chosen to agree with hand fit smoothing methods, so as to obtain a smoothed velocity profile. The smoothed data is processed to obtain and display an acceleration profile and a displacement profile, as well as data points for peak acceleration, time at peak, acceleration pulse width, muzzle exit velocity and time at exit.

Abstract: A method is provided to capture and process wire guidance fire control command tones. The method is implemented on a computer, which monitors and displays the wire guidance command tones in real time, showing the tone or signal over time. A user controls the beginning and ending of the capture period. The captured data is stored within the computer. Once data capturing has ended, the full record of the captured data is displayed. The display includes active cursors denoting the start and stop of the recorded event. The cursors may be positioned independently along the data display so as to bracket a tone event of interest. Once the cursors are positioned, the method updates the display to show only the bracketed event. The time duration of the event is also shown as well as a computed frequency for the event. The user may then continue refining the positions of the cursors to accurately identify the event of interest.

Abstract: A method is provided to determine an rpm profile for a turbine pump from pulse train data obtained from a sensor at the pump. The method eliminates ramp-up spikes from the pulse train by comparing the spike pulse count to the surrounding pulse counts and replacing data points responsible for abnormal pulse count increases/decreases between data points with interpolated values. The method similarly replaces data points that lie outside statistically acceptable pulse rate variations. A rough rpm plot is then generated, which must be smoothed to obtain the final rpm profile. Data points are infused between sensor data points to achieve an acquisition rate of approximately 1000 points per second. The infusion is accomplished by interpolating between sensor data points and equally spacing the infused data points along the interpolated curve. A smoothing function is then applied to the infused data set.

Abstract: A processing system and method is used to process acoustic and non-acoustic test data acquired from a number of data collectors. The post-processing system and method is implemented as software and hardware capable of running on a PC. The processing system interfaces with a data acquisition (DAQ) system that acquires calibration signals and test data from the data collectors at a test facility. The processing system uses the calibration signals to determine calibration factors representing the relationship between the test data and the appropriate engineering units. The processing system processes the acoustic and non-acoustic test data, applies the appropriate calibrations factors, and plots the acoustic and non-acoustic test data as a function of time to generate run-time plots. Data values are stored and plotted against calculated baseline curves to generate envelope or baseline plots of the collected data.

Abstract: A portable data acquisition system for use in certifying torpedo tube-launched weapons such as a Mark 48/ADCAP, a Tomahawk missile or a Harpoon and the like. The system includes a portable computer, a rugged four slot chassis, a 32 channel multiplexing module, a four channel isolation amplifier with excitation, eight channel isolation amplifier, a custom signal conditioning module, an associated terminal block and interface cables. The system has the unique feature of obtaining live data for quick analysis about the launched weapon using the torpedo tube as opposed to the post launch data for analysis. All the components are housed in a shock resilient and weather-tight container.