Abstract: A radar target simulator for simulating radar targets is provided. The radar target simulator has an analogue-to-digital converter having a first clock generator and a digital-to-analogue converter having a second clock generator. The analogue-to-digital converter is configured to receive a radar signal transmitted by a radar system as an input signal, while the digital-to-analogue converter is configured to return an output signal to the radar system for simulation of the radar target. Further, the first and the second clock generator are configured to operate the analogue-to-digital converter and the digital-to-analogue converter at a different sampling rate in each case.

Abstract: A combined statistical-deterministic approach to methods and systems for assessing risk associated with natural disasters, in particular, hurricane wind risk. One example of a method of predicting wind speed distribution within a predetermined distance from a point of interest includes steps of statistically synthesizing a large plurality of wind storm tracks that pass within a predetermined radius of the point of interest, running a deterministic simulation of wind intensity along each one of the large plurality of wind storm tracks to produce an output representative of wind speed distribution along each track, and using the output to estimate an overall wind speed probability distribution from a combination of the wind speed distributions along each track within the predetermined distance from the point of interest.

Abstract: It is useful to a sonar instructor to have a device which simulates Doppler hifting of recorded sonar signals. Such a device can consist of a digitizer operating at a fixed rate storing data in RAM. A variable read rate is calculated based on the desired Doppler shifting. Data are read from RAM at a variable rate higher or lower than the fixed rate and converted D to A before being sent to the student sonar operator.

Abstract: A simulator of bottom return signals for a sonar system on a moving ship generates pulsed frequency modulated signals to simulate ocean bottom returns. Signals from the sonar transmitter are stretched in accordance with a postulated bottom configuration and applied to the frequency modulators to provide frequency modulated signals for the duration of the stretched pulses. Noise is simulated with the addition of an appropriate sinusoidal signal to each pulsed frequency modulated signal.

Abstract: A thermoplastic resin composition for cleaning a shaping apparatus such as an extrude by a simple operation, comprising 2-30% by weight of a sodium salt of sulfonic acid, 0.5-10% by weight of a water-repellent compound and a thermoplastic resin and as an optional component, finely ground inorganic compound having a particle size of 0.005 to 10 .mu.m.

Abstract: A broadband doppler simulator is described in which signals from a plurality of hydrophones are simulated by selecting storage addresses of a random access memory whose successive addresses contain samples of an input signal. The range of each hydrophone from the target whose signal it is receiving is determined by the address assigned to the hydrophone relative to the address of the input signal in the random access memory. In order to produce a doppler shift (time compression/expansion), the address of the simulated hydrophone signal is changed with respect to the signal which is being stored in the memory. The rate at which the address of the simulated hydrophone signal is being changed relative to the input signal determines the doppler shift.

Abstract: 2.