Abstract: An ultrasonic measurement apparatus has an ultrasonic transducer device including an ultrasonic element array, a first through n-th first end-side terminal XA1 to XAn provided to a first end side, and a first through n-th second end-side terminal XB1 to XBn provided to a second end side opposing the first end side; a first transmission circuit outputting first drive signals VTA1 to VTAn to the first through n-th first end-side terminals XA1 to XAn; and a second transmission circuit outputting second drive signals VTB1 to VTBn to the first through n-th second end-side terminals XB1 to XBn.

Abstract: A remote targeting apparatus and method comprising surrounding a projectile target with a sensor array, computing projectile impact data, transmitting the data receiving the data at a controller; and displaying information corresponding to the data. RF transmission/reception is performed, most preferably at a frequency of between approximately 902 and 928 MHz, with the controller having RF Faraday cage shielding and collision avoidance being employed to permit multiple sensor arrays to operate in a vicinity of one another. Projectile impact locations within twelve inches of the center of the projectile target are calculated to an average RMS accuracy of less than approximately fifty thousandths of an inch, directly in an orthogonal Cartesian coordinate system. Velocity is also determined via an additional sensor at a predetermined distance from the sensor array which measures a difference in time between the projectile passing the additional sensor and the sensor array.

Abstract: A sonar countermeasure comprising a decoy device that carries apparatus for eceiving, processing and transmitting sonar signals. Processing apparatus includes magnetic tape storage, staggered record and read heads and time varying partial erase heads which produce realistic "echo" of received sonar search signals.

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 plurality of hydrophone output signals representative of an ocean bottom re simulated to test a receiver of the sonar sounding system. The phase shift of the output of each hydrophone at each snapshot is determined along with the amplitude. This information is stored for use during simulation. During the simulation, a carrier signal, along with the recorded phase shift amplitude information, are applied to a phase shifter to phase shift the carrier signal in accordance with the recorded phase shift data for each channel and attenuate the phase shifted signal. The phase shifted and attenuated output is applied to a channel of a receiver of the sonar sounding system. Two phase shift words representative of the phase shift of the hydrophone can modulate a master and a delayed master respectively to provide better results. The phase shift data may be selectively applied to the receiver of the sonar sounding system to test the receiver at a plurality of different resolutions.

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: A target simulator tests the characteristics of a multi-element array witt the use of large memories and long delay line storage. The simulator includes a master clock which provides the count frequency to a binary counter. The reading of the binary counter is compared in a comparator with a stored number in a sequence from a programmable readable memory (PROM). On agreement the comparator feeds an output to an appropriate member of a group of hydrophone counters. Upon receipt of the signal from the comparator the counter provides a signal to the PROM. The PROM then provides its next synchronizing binary number to the comparator. The hydrophone counter also provides a signal to the channel selector reset which resets an appropriate pseudo-random noise generator (PRNG) to produce an output of the target simulator.