High-Resolution 3-Dimensional Radar Imaging Based on a Few-Cycle W-band Photonic Millimeter-Wave Pulse Generator

Author(s):  
Tzu-Fang Tseng ◽  
Jhih-Min Wun ◽  
Wei Chen ◽  
Sui-Wei Peng ◽  
Jin-Wei Shi ◽  
...  
2013 ◽  
Vol 21 (12) ◽  
pp. 14109 ◽  
Author(s):  
Tzu-Fang Tseng ◽  
Jhih-Min Wun ◽  
Wei Chen ◽  
Sui-Wei Peng ◽  
Jin-Wei Shi ◽  
...  

2021 ◽  
Vol 13 (17) ◽  
pp. 3366
Author(s):  
Shunjun Wei ◽  
Zichen Zhou ◽  
Mou Wang ◽  
Jinshan Wei ◽  
Shan Liu ◽  
...  

Millimeter-wave (MMW) 3-D imaging technology is becoming a research hotspot in the field of safety inspection, intelligent driving, etc., due to its all-day, all-weather, high-resolution and non-destruction feature. Unfortunately, due to the lack of a complete 3-D MMW radar dataset, many urgent theories and algorithms (e.g., imaging, detection, classification, clustering, filtering, and others) cannot be fully verified. To solve this problem, this paper develops an MMW 3-D imaging system and releases a high-resolution 3-D MMW radar dataset for imaging and evaluation, named as 3DRIED. The dataset contains two different types of data patterns, which are the raw echo data and the imaging results, respectively, wherein 81 high-quality raw echo data are presented mainly for near-field safety inspection. These targets cover dangerous metal objects such as knives and guns. Free environments and concealed environments are considered in experiments. Visualization results are presented with corresponding 2-D and 3-D images; the pixels of the 3-D images are 512×512×6. In particular, the presented 3DRIED is generated by the W-band MMW radar with a center frequency of 79GHz, and the theoretical 3-D resolution reaches 2.8 mm × 2.8 mm × 3.75 cm. Notably, 3DRIED has 5 advantages: (1) 3-D raw data and imaging results; (2) high-resolution; (3) different targets; (4) applicability for evaluation and analysis of different post processing. Moreover, the numerical evaluation of high-resolution images with different types of 3-D imaging algorithms, such as range migration algorithm (RMA), compressed sensing algorithm (CSA) and deep neural networks, can be used as baselines. Experimental results reveal that the dataset can be utilized to verify and evaluate the aforementioned algorithms, demonstrating the benefits of the proposed dataset.


1966 ◽  
Vol 54 (1) ◽  
pp. 71-72 ◽  
Author(s):  
S. Kita ◽  
S. Seki

Author(s):  
J. Jakana ◽  
M.F. Schmid ◽  
P. Matsudaira ◽  
W. Chiu

Actin is a protein found in all eukaryotic cells. In its polymerized form, the cells use it for motility, cytokinesis and for cytoskeletal support. An example of this latter class is the actin bundle in the acrosomal process from the Limulus sperm. The different functions actin performs seem to arise from its interaction with the actin binding proteins. A 3-dimensional structure of this macromolecular assembly is essential to provide a structural basis for understanding this interaction in relationship to its development and functions.


Author(s):  
Colin F. Wilson ◽  
Thomas Widemann ◽  
Richard Ghail

AbstractIn this paper, originally submitted in answer to ESA’s “Voyage 2050” call to shape the agency’s space science missions in the 2035–2050 timeframe, we emphasize the importance of a Venus exploration programme for the wider goal of understanding the diversity and evolution of habitable planets. Comparing the interior, surface, and atmosphere evolution of Earth, Mars, and Venus is essential to understanding what processes determined habitability of our own planet and Earth-like planets everywhere. This is particularly true in an era where we expect thousands, and then millions, of terrestrial exoplanets to be discovered. Earth and Mars have already dedicated exploration programmes, but our understanding of Venus, particularly of its geology and its history, lags behind. Multiple exploration vehicles will be needed to characterize Venus’ richly varied interior, surface, atmosphere and magnetosphere environments. Between now and 2050 we recommend that ESA launch at least two M-class missions to Venus (in order of priority): a geophysics-focussed orbiter (the currently proposed M5 EnVision orbiter – [1] – or equivalent); and an in situ atmospheric mission (such as the M3 EVE balloon mission – [2]). An in situ and orbital mission could be combined in a single L-class mission, as was argued in responses to the call for L2/L3 themes [3–5]. After these two missions, further priorities include a surface lander demonstrating the high-temperature technologies needed for extended surface missions; and/or a further orbiter with follow-up high-resolution surface radar imaging, and atmospheric and/or ionospheric investigations.


2007 ◽  
Vol 539-543 ◽  
pp. 2353-2358 ◽  
Author(s):  
Ulrich Lienert ◽  
Jonathan Almer ◽  
Bo Jakobsen ◽  
Wolfgang Pantleon ◽  
Henning Friis Poulsen ◽  
...  

The implementation of 3-Dimensional X-Ray Diffraction (3DXRD) Microscopy at the Advanced Photon Source is described. The technique enables the non-destructive structural characterization of polycrystalline bulk materials and is therefore suitable for in situ studies during thermo-mechanical processing. High energy synchrotron radiation and area detectors are employed. First, a forward modeling approach for the reconstruction of grain boundaries from high resolution diffraction images is described. Second, a high resolution reciprocal space mapping technique of individual grains is presented.


2013 ◽  
Author(s):  
Jonathan Tedeschi ◽  
Bruce Bernacki ◽  
Dave Sheen ◽  
Jim Kelly ◽  
Doug McMakin
Keyword(s):  

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