Wavefront Coded Imaging Systems for MEMS Analysis

Author(s):  
Daniel L. Barton ◽  
Jeremy A. Walraven ◽  
Edward R. Dowski ◽  
Rainer Danz ◽  
Andreas Faulstich ◽  
...  

Abstract A new imaging technique called Wavefront Coding allows real-time imaging of three-dimensional structures over a very large depth. Wavefront Coding systems combine aspheric optics and signal processing to achieve depth of fields ten or more times greater than that possible with traditional imaging systems. Understanding the relationships between traditional and modern imaging system design through Wavefront Coding is very challenging. In high performance imaging systems nearly all aspects of the system that could reduce image quality are carefully controlled. Modifying the optics and using signal processing can increase the amount of image information that can be recorded by microscopes. For a number of applications this increase in information can allow a single image to be used where a number of images taken at different object planes had been used before. Having very large depth of field and real-time imaging capability means that very deep structures such as surface micromachined MEMS can be clearly imaged with one image, greatly simplifying defect and failure analysis.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christopher Schwäbig ◽  
Siying Wang ◽  
Sabine Gütgemann

Abstract The following article describes the development of a millimetre wave based real-time imaging system for three dimensional non-destructive testing of goods. For this purpose a rotating antenna is used which is fed from an FMCW radar. The received measuring data is processed with a SAR algorithm. Due to the fact that a reflexive measurement method is used, the integration of the system into existing systems is simplified. To make the computing power-intensive SAR image processing possible, the complete signal processing chain of the image processing is executed on the graphics card. The article elucidates the concept for calculating the measurement parameters which have to be elaborated for the implementation of the image processing of the whole system.


2019 ◽  
Vol 436 ◽  
pp. 232-238
Author(s):  
Xutao Mo ◽  
Tao Zhang ◽  
Bin Wang ◽  
Xianshan Huang ◽  
Cuifang Kuang ◽  
...  

2011 ◽  
Vol 50 (4) ◽  
pp. 859-872 ◽  
Author(s):  
Valery M. Melnikov ◽  
Dusan S. Zrnić ◽  
Richard J. Doviak ◽  
Phillip B. Chilson ◽  
David B. Mechem ◽  
...  

AbstractSounding of nonprecipitating clouds with the 10-cm wavelength Weather Surveillance Radar-1988 Doppler (WSR-88D) is discussed. Readily available enhancements to signal processing and volume coverage patterns of the WSR-88D allow observations of a variety of clouds with reflectivities as low as −25 dBZ (at a range of 10 km). The high sensitivity of the WSR-88D, its wide velocity and unambiguous range intervals, and the absence of attenuation allow accurate measurements of the reflectivity factor, Doppler velocity, and spectrum width fields in clouds to ranges of about 50 km. Fields of polarimetric variables in clouds, observed with a research polarimetric WSR-88D, demonstrate an abundance of information and help to resolve Bragg and particulate scatter. The scanning, Doppler, and polarimetric capabilities of the WSR-88D allow real-time, three-dimensional mapping of cloud processes, such as transformations of hydrometeors between liquid and ice phases. The presence of ice particles is revealed by high differential reflectivities and the lack of correlation between reflectivity and differential reflectivity in clouds in contrast to that found for rain. Pockets of high differential reflectivities are frequently observed in clouds; maximal values of differential reflectivity exceed 8 dB, far above the level observed in rain. The establishment of the WSR-88D network consisting of 157 polarimetric radars can be used to collect cloud data at any radar site, making the network a potentially powerful tool for climatic studies.


2008 ◽  
Vol 28 (5) ◽  
pp. 870-875 ◽  
Author(s):  
潘超 Pan Chao ◽  
陈家璧 Chen Jiabi ◽  
张荣福 Zhang Rongfu ◽  
庄松林 Zhuang Songlin

2011 ◽  
Vol 18 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Masato Hoshino ◽  
Kentaro Uesugi ◽  
James Pearson ◽  
Takashi Sonobe ◽  
Mikiyasu Shirai ◽  
...  

An X-ray stereo imaging system with synchrotron radiation was developed at BL20B2, SPring-8. A portion of a wide X-ray beam was Bragg-reflected by a silicon crystal to produce an X-ray beam which intersects with the direct X-ray beam. Samples were placed at the intersection point of the two beam paths. X-ray stereo images were recorded simultaneously by a detector with a large field of view placed close to the sample. A three-dimensional wire-frame model of a sample was created from the depth information that was obtained from the lateral positions in the stereo image. X-ray stereo angiography of a mouse femoral region was performed as a demonstration of real-time stereo imaging. Three-dimensional arrangements of the femur and blood vessels were obtained.


2016 ◽  
Vol 110 (3) ◽  
pp. 463a
Author(s):  
Fuyu Kobirumaki-Shimozawa ◽  
Kotaro Oyama ◽  
Togo Shimozawa ◽  
Takashi Ohki ◽  
Takako Terui ◽  
...  

1975 ◽  
Author(s):  
A. E. Stewart

This paper discusses the development of a real-time high energy x-ray imaging system for use in dynamic fluoroscopy of aero gas turbines. In order to cover the range of subjects on gas turbines, over ten combinations of film and screen types are used. Three different types of x-ray imaging systems were considered for use: direct type intensifiers (cesium iodide phosphors), and indirect type intensifiers — Marconi “Marionette” and the Oude Delft “Delcalix.”


Sign in / Sign up

Export Citation Format

Share Document