An improved range-resolution pulse-echo technique by means of vectorial-network-analyzer-based frequency-domain testing

1994 ◽  
Vol 41 (3) ◽  
pp. 418-420
Author(s):  
M. Bramanti
Keyword(s):  
Frequency Domain ◽  
Network Analyzer ◽  
Range Resolution ◽  
Pulse Echo

scholarly journals Precision Imaging of Frequency Stepped SAR with Frequency Domain Extracted HRRP and Fast Factorized Back Projection Algorithm

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Can-bin Yin ◽  
Da Ran
Keyword(s):  
Fourier Transform ◽  
Frequency Domain ◽  
Single Point ◽  
Projection Algorithm ◽  
Great Promise ◽  
Back Projection ◽  
Imaging Processing ◽  
Block Partition ◽  
Range Resolution ◽  
High Range

Novel frequency domain extracted method (FDEM) to obtain high range resolution profile (HRRP) for frequency stepped synthetic aperture radar (SAR) is proposed in this paper, and the mathematical principle and formulas of this new HRRP obtaining idea combined with classical fast Fourier transform (FFT), chirp z transform (CZT), and single point Fourier transform (SPFT) are deduced, analyzed, and compared in detail. Based on the HRRP data, precision imaging processing is completed using a data block partition based fast factorized back projection algorithm. Imaging validations are executed and all results proved that the FDEM has a great capability of antijamming. It is more effective than conventional time domain IFFT method (TDM) and shows a great promise in frequency stepped radar imaging and applications.

Ultrasonic Extension Sensing of Actuators Using Integrated Piezoelectric Transducer for Adaptive Optics

2008 ◽  
Vol 56 ◽  
pp. 70-75 ◽  
Author(s):  
Shin Sung Kim ◽  
A. Erman Uzgur ◽  
Mel Strachan ◽  
Jean François Saillant ◽  
Katherine Kirk
Keyword(s):  
Frequency Domain ◽  
Travel Time ◽  
Adaptive Optics ◽  
Ultrasonic Transducer ◽  
Ultrasonic Pulse ◽  
Ultrasonic Techniques ◽  
The Time Domain ◽  
Frequency Domain Approach ◽  
Pulse Echo ◽  
Multilayer Actuators

Ultrasonic techniques have been proposed to determine the extension of piezoelectric multilayer actuators which can be used to construct deformable mirrors for adaptive optics. In the time domain approach, pulse-echo measurements were carried out using an ultrasonic transducer integrated with the actuator. In the frequency domain approach, the frequency shift of the integrated transducer was used to estimate the extension by analysis of the resonant spectrum for impedance magnitude. Time and frequency domain measurements were carried out on large actuators (7×7×28 mm3). Frequency domain measurements were carried out on smaller actuators (2×2×2 mm3) which are more suitable for a miniaturised deformable mirror. Monolithic integration of the ultrasonic extension sensing transducer and the actuator was demonstrated using layers in the multilayer actuators. Strong correlation was observed between the travel time of the ultrasonic pulse through the actuator and the simultaneously-measured actuator extension. It was noted, contrary to common prediction, that the travel time of the signal was earlier when the actuator was extended. Results are presented on the development of the device design, the characteristics of the prototype device and the accuracy of the sensing techniques.

High-range-resolution imaging using frequency domain interferometry with stabilization techniques for real-time vascular ultrasound

2015 ◽  
Vol 54 (7S1) ◽  
pp. 07HF05 ◽  
Author(s):  
Hirofumi Taki ◽  
Kousuke Taki ◽  
Makoto Yamakawa ◽  
Tsuyoshi Shiina ◽  
Motoi Kudo ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Real Time ◽  
Range Resolution ◽  
Vascular Ultrasound ◽  
Resolution Imaging ◽  
High Range
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