Ultrasonic transmitting, receiving and amplifying circuits are designed. Thereceived signals are sampled with the high speed ADC (analog-to-digital converter), and dealt withthe DSP (digital signal processing). A forw...Ultrasonic transmitting, receiving and amplifying circuits are designed. Thereceived signals are sampled with the high speed ADC (analog-to-digital converter), and dealt withthe DSP (digital signal processing). A forward-backward IIR (infinitive impulse response) filterwith no delay is designed to filter the sampled data, and series A and B are achieved by narrow andwide band filtering, respectively. In series A, the start point of the cycle first exceeding thethreshold is calculated accuratelyby interpolation, and the start cycle is detected by fittingcycles in series A and its inversion A' to cycles in B with variance analysis. Therefore, the startpoint of the start cycle is calculated precisely. By deriving the relationships between the traveltime in the opposite directions of three axes and the airflow velocities, the wind velocity anddirection are calculated. Experiments show that the reliability and the precision are improved, andthe circuits are simplified.展开更多
The.functions of a general target simulator are too few to provide the sonar equipmentand sonar signal-Processing algorithm with a set of integrated experimental data. In this paper anew universal target simulator is ...The.functions of a general target simulator are too few to provide the sonar equipmentand sonar signal-Processing algorithm with a set of integrated experimental data. In this paper anew universal target simulator is developed based on the sound scattering theory. It can produceintegrated simulated data for the various existing sonar equipment and the usual sonar signalprocessing algorithms. The means and efficiency of detection of sonar equipment are improvedby this new simulator In the meantime, this new device stimulates the research on sonar signalprocessing algorithms.展开更多
文摘Ultrasonic transmitting, receiving and amplifying circuits are designed. Thereceived signals are sampled with the high speed ADC (analog-to-digital converter), and dealt withthe DSP (digital signal processing). A forward-backward IIR (infinitive impulse response) filterwith no delay is designed to filter the sampled data, and series A and B are achieved by narrow andwide band filtering, respectively. In series A, the start point of the cycle first exceeding thethreshold is calculated accuratelyby interpolation, and the start cycle is detected by fittingcycles in series A and its inversion A' to cycles in B with variance analysis. Therefore, the startpoint of the start cycle is calculated precisely. By deriving the relationships between the traveltime in the opposite directions of three axes and the airflow velocities, the wind velocity anddirection are calculated. Experiments show that the reliability and the precision are improved, andthe circuits are simplified.
文摘The.functions of a general target simulator are too few to provide the sonar equipmentand sonar signal-Processing algorithm with a set of integrated experimental data. In this paper anew universal target simulator is developed based on the sound scattering theory. It can produceintegrated simulated data for the various existing sonar equipment and the usual sonar signalprocessing algorithms. The means and efficiency of detection of sonar equipment are improvedby this new simulator In the meantime, this new device stimulates the research on sonar signalprocessing algorithms.
