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Time Lens with Improved Aperture to Resolution Ratio Based on a Phase Modulator
2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring), 2019A time lens with improved aperture to resolution ratio is proposed, which is composed of a series of splitted quadrature phase, realized by using a phase modulator with low half-wave voltage and a splitted parabolic driving signal. By splitting the standard parabolic driving signal into $2N$ pieces within the same time aperture, the temporal ...
Bowen Zhang +3 more
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Thermal emission from periodic array of microcavities with a different aperture ratio
Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, 2003Summary form only given. Recent studies of thermal emission control have revealed many interesting phenomena. The influence of microstructures upon thermal emission, however, has not well been understood. In this paper, we report experimental results of thermal emission from a tantalum surface having a periodic array of microcavities.
F. Kusunoki, J. Takahara, T. Kobayashi
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On the optimisation of distributed ambiguity ratio and directivity for a synthetic aperture radar
26th European Microwave Conference, 1996, 1996Space borne Synthetic Aperture Radar (SAR) is a radar capable of high resolution imaging of the surface of the earth. Typical applications of a space borne SAR include the observation of oil slicks, ice packs, shipping lanes, industrial pollution and agricultural usage. The SAR spacecraft travels in a low earth orbit focusing a narrow radiation pattern
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Estimator and signal-to-noise ratio for an integrative synthetic aperture imaging technique
Applied Optics, 1991An imaging system is described which uses the following concepts: laser illumination of objects, nonredundant apertures, and phase closure. A sparse transmitter array is envisioned, each aperture of which emits at a different laser frequency such that any pair of beams gives rise to a unique beat signal. The light reflected by an object thus irradiated
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On the signal-to-noise ratio of a synthetic aperture ultrasound imaging method
European Journal of Ultrasound, 1996Abstract Conventional synthetic aperture ultrasound imaging requires wide angular response of the probe which presumes the use of a narrow transducer element. As a result the signal-to-noise ratio and the contrast resolution become poor. The problem can be overcome by using a multielement subarray and making the beam narrower.
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Zernike representation and Strehl ratio of optical systems with variable numerical aperture
Journal of Modern Optics, 2008We consider optical systems with variable numerical aperture (NA) on the level of the Zernike coefficients of the correspondingly scalable pupil function. We thus present formulas for the Zernike coefficients and their first two derivatives as a function of the scaling factor 1, and we apply this to the Strehl ratio and its derivatives of NA-reduced ...
Janssen, A.J.E.M. +3 more
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Ambiguity validation with combined ratio test and ellipsoidal integer aperture estimator
Journal of Geodesy, 2010To ensure reliable ambiguity resolution, ambiguity validation is an indispensable step. It has been a challenge for many years and is far from being resolved. Over the past years, various ambiguity validation methods have been proposed, such as F-ratio test, R-ratio test, difference test, projector test, ellipsoidal integer aperture (EIA) estimator and
Shengyue Ji +5 more
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Effects of Abscisic Acid and its Esters on Stomatal Aperture and the Transpiration Ratio
Physiologia Plantarum, 1972AbstractA single surface application of abscisic acid or its methyl and phenyl esters suppressed stomatal opening on leaves of Xanthium strumarium. The effect was restricted to the treated parts of the leaf blades, there being no detectable translocation to untreated parts.
RUTH J. JONES, T. A. MANSFIELD
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Dual‐band shared‐aperture antenna with high aperture reuse ratio and high isolation
International Journal of RF and Microwave Computer-Aided Engineering, 2022Huayan Jin +4 more
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On the concept of field-to-resolution ratio in aperture synthesis.
1994The analysis of the imaging properties of an interferometric device essentially depends on the parameteres that govern the Fourier synthesis operation: extension and density of the experimental frequency coverage (resolution, field, robustness), size and nature of the input errors (input data for the study of the error propagation).
Lannes, André +3 more
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