The Plane Wave Spectrum Representation of Electromagnetic Fields

In many applications, such as development and testing of image processing algorithms, it is often necessary to simulate images containing realistic noise from solid-state photosensors. A high-level model of CCD and CMOS photosensors based on a literature review is formulated in this paper. The model includes photo-response non-uniformity, photon shot noise, dark current Fixed Pattern Noise, dark current shot noise, offset Fixed Pattern Noise, source follower noise, sense node reset noise, and quantisation noise. The model also includes voltage-to-voltage, voltage-to-electrons, and analogue-to-digital converter non-linearities. The formulated model can be used to create synthetic images for testing and validation of image processing algorithms in the presence of realistic images noise. An example of the simulated CMOS photosensor and a comparison with a custom-made CMOS hardware sensor is presented. Procedures for characterisation from both light and dark noises are described. Experimental results that confirm the validity of the numerical model are provided. The paper addresses the issue of the lack of comprehensive high-level photosensor models that enable engineers to simulate realistic effects of noise on the images obtained from solid-state photosensors.

High-level numerical simulations of noise in CCD and CMOS photosensors: review and tutorial.

In this paper we analyse the response of two different Commercial Off The shelf CMOS image sensors as particle detectors. Sensors were irradiated using X-ray photons, gamma photons, beta particles and alpha particles from diverse sources. The amount of charge produced by different particles, and the size of the spot registered on the sensor are compared, and analysed by an algorithm to classify them. For a known incident energy spectrum, the employed sensors provide a dose resolution lower than microGray, showing their potentials in radioprotection, area monitoring, or medical applications.

Particle detection and classification using commercial off the shelf CMOS image sensors

Estimation of the blurring effect is very important for many imaging systems. This letter reports an idea to efficiently and robustly compute the blurring parameter on certain stripe edges. Two formulas are found to determine the degree of imaging blur only by calculating the area sizes under the corresponding profile curves, without the need for deconvolution or transformation over the image. The method can be applied to many applications such as vision sensing of scene depth. A 3-D vision system is taken as an implementation instance.

Determination of Stripe Edge Blurring for Depth Sensing

Multispectral (MS) images provided by Earth observation satellites have generally a poor spatial resolution while panchromatic images (PAN) exhibit a spatial resolution two or four times better Data fusion is a means to synthesize MS images at higher spatial resolution than original by exploiting the high spatial resolution of the PAN This process is often called pansharpening The synthesis property states that the synthesized MS images should be as close as possible to those that would have been acquired by the corresponding sensors if they had this high resolution The methods based on the concept Amelioration de la Resolution Spatiale par Injection de Structures (ARSIS) are able to deliver synthesized images with good spectral quality but whose geometrical quality can still be improved We propose a more precise definition of the synthesis property in terms of geometry Then, we present a method that takes explicitly into account the difference in modulation transfer function (MTF) between PAN and MS in the fusion process This method is applied to an existing ARSIS-based fusion method, ie, A trou wavelet transform-model 3 Simulated images of the sensors Pleiades and SPOT-5 are used to illustrate the performances of the approach Although this paper is limited in methods and data, we observe a better restitution of the geometry and an improvement in all indices classically used in quality budget in pansharpening We present also a means to assess the respect of the synthesis property from an MTF point of view

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A Method to Better Account for Modulation Transfer Functions in ARSIS-Based Pansharpening Methods

In this paper the lateral photoresponse and crosstalk (CTK) in complementary metal-oxide-semiconductor (CMOS) photodiodes is investigated by means of a unique sub-micron scanning system (S-cube system) and numerical device simulation. An improved semi-analytical model developed for photoresponse estimation of a photodiode-based CMOS active pixel sensor reveals the photosignal and the CTK dependence on the pixels geometrical shape and arrangement within the array. The trends that promise to increase CMOS image sensor performance are presented and design tradeoffs intended to optimize the photoresponse and minimize CTK are discussed.

A comprehensive CMOS APS crosstalk study: photoresponse model, technology, and design trends

In this work, a fully theoretical CMOS active pixel sensor (APS) modulation transfer function model is formulated, evaluated, and compared with practical results. The model is based on a two-dimensional diffusion equation solution and covers the symmetrical photocarriers diffusion effect together with the impact of the pixel active area geometrical shape. Thorough scanning results obtained by means of a unique submicron scanning system (the S-cube system) from various APS chips, implemented in a standard CMOS 0.35-/spl mu/m technology, are compared with our theoretical predictions. The agreement of the presented comparison results indicates that for any potential active area shape, an analytical reliable estimate of image performance is possible.

Theoretical approach to CMOS APS PSF and MTF modeling - evaluation

The present contribution is concerned with obtaining plane-wave spectral representations of the relativistic electric and magnetic dyadic Green's functions of an isotropic dielectric-magnetic medium (at the frame-at-rest) that is moving in a uniform velocity. By applying a simple coordinate transformation, scalarization of the EM vectorial problem is obtained in which the EM dyads are evaluated from Helmholtz's isotropic scalar Green's function. The spectral plane-wave representations of the dyadic Green's functions are obtained by applying the spatial 2D Fourier transform to the scalar Green's function. We investigate these spectral representations in the under and over phase-speed regimes, as well as 2D and 3D formulations and discuss the associated wave phenomena.

Spectral Analysis of Relativistic Dyadic Green's Function of a Moving Dielectric-Magnetic Medium

The present contribution is concerned with deriving the relativistic electric and magnetic time-dependent dyadic Green's functions of an isotropic dielectric-magnetic medium (at the frame-at-rest) that is moving in a uniform relativistic velocity under the framework of the Minkowski constitutive relations. The results presented here correct previous reports in the literature [R. Compton, J. Math. Phys. 7, 2145 (1966)] and [C. Tai, J. Math. Phys. 8, 646 (1967)]. By applying a simple space-time and fields-sources transformation, scalarization of the vectorial problem is obtained. Thus the electromagnetic dyads are evaluated from the Green's function of the scalar (time-dependent) wave equation in free space. Emphasis is placed on a simple and direct time domain derivation.

A Simple and Direct Time Domain Derivation of the Dyadic Green's Function for a Uniformly Moving Non-Dispersive Dielectric-Magnetic Medium

This work shows the progress and demonstrates the measurements performed via a unique submicron scanning system developed at the VLSI systems center in Ben-Gurion University.
The system enables the combination of near-field optical and atomic force microscopy measurements with the standard electronic analysis. The obtained signal, i.e., the electrical outcome at each point as a function of the spot position provides a 2D signal map of the pixel response, representing the full 3D charge distribution in the device. 
This work present the results obtained by thorough scanning of several various pixel topologies of CMOS APS chips fabricated in two different CMOS technologies (the standard 0.5μm and 0.35μm CMOS technologies). 
We demonstrate that our system use enables a detailed, point by point, quantitative determination of the contributions to the total output signal from each particular region of the pixel. It makes possible to understand the influence of the each component composing the pixel (e.g., logic transistors, metal lines, etc.) which is extremely important for CMOS APS where the pixel structure defines a fill factor of less then 100%.

T. Danov

Papers

A comprehensive CMOS APS crosstalk study: photoresponse model, technology, and design trends

Theoretical approach to CMOS APS PSF and MTF modeling - evaluation

Spectral Analysis of Relativistic Dyadic Green's Function of a Moving Dielectric-Magnetic Medium

A Simple and Direct Time Domain Derivation of the Dyadic Green's Function for a Uniformly Moving Non-Dispersive Dielectric-Magnetic Medium

Point-by-point thorough photoresponse analysis of CMOS APS by means of our unique submicron scanning system