Statistical scene generation for polarimetric imaging systems

Little publicly available data exists for polarimetric measurements. When designing task specific polarimetric systems, the statistical properties of the task specific data becomes important. Until better polarimetric datasets are available to deduce statistics from, the statistics must be simulated to test instrument performance. Most imaged scenes have been shown to follow a power law power spectral density distribution, for both natural and city scenes. Furthermore, imaged data appears to follow a power law power spectral distribution temporally. We are interested in generating image sets which change over time, and at the same time are correlated between different components (spectral or polarimetric). In this brief communication, we present a framework and provide code to generate such data.Comment: 5 pages, 3 figures, 3 matlab function

Strengthening Biblical Historicity vis-a`-vis Minimalism, 1992–2008 and Beyond. Part 2.3: Some Commonalities in Approaches to Writing Ancient Israel’s History

This series of articles covers scholarly works in English which can, at least potentially, be associated with a generally positive view of biblical historicity regarding periods preceding the Israelites’ return from exile. Part 2 covers works that treat the methodological issues at the center of the maximalist–minimalist debate. Parts 2.1 and 2.2 selectively survey the works of 24 non-minimalist scholars during two decades. In the absence of consensus, this article analyzes the works in Parts 2.1 and 2.2, tracing elements of approach that are held in common, at least among pluralities of non-minimalists (possible majorities are not noted). The first commonality of approach is that history is provisional, not final. The second is that history should become fully multidisciplinary. The third commonality is that historians should receive all historical evidence on an equal footing before examination and cross-examination. The fourth and last is that historians should become increasingly sensitive to cultural aspects and coding in ancient Near Eastern materials

Neonatal Fc Receptor: From Immunity to Therapeutics

The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn

The imaging equation for a microgrid linear Stokes polarimeter

ABSTRACT Imaging polarimeters have currently and historically been largely used for remote sensing tasks. They have also been used to evaluate the defects and calibrate the polarization of liquid crystal displays. A particular type of polarimeter that has a great deal of unrealized potential is the microgrid array linear Stokes polarimeter. This type of polarimeter is not often used because of reconstruction errors. If these errors could be minimized, or mitigated via proper algorithmic reconstruction, then they have advantages over other types of polarimeters, mainly calibration (not much is needed) and proper operation over wide wavelength bands (due to the use of wire grid linear polarizers). In the paper I analyze the imaging equation of the microgrid Stokes polarimeter, using the full vectorial electric field

Noise reduction in a laser polarimeter based on discrete waveplate rotations

While several analyses of polarimeter noise-reduction have been published, little data has been presented to support the analytical results, particularly for a laser polarimeter based on measurements taken at discrete, independent rotation angles of two birefringent waveplates. This paper derives and experimentally demonstrates the reduction of both system and speckle noise in this type of laser polarimeter, achieved by optimizing the rotation angles of the waveplates by minimizing the condition numbers of the appropriate matrix equation. Results are demonstrated experimentally in signal-to-noise ratio (SNR) variations for a range of materials and spatial bandwidths. Use of optimal waveplate angles is found to improve the average SNR of the normalized Mueller matrix over speckle by a factor of up to 8 for a non-depolarizing material, but to provide little improvement for a depolarizing material. In the limit of zero spatial bandwidth, the average SNR of the normalized Mueller matrix over speckle is found to be greater than one for a non-depolarizing material and less than one for a depolarizing material

Optimal bandwidth and systematic error of full-Stokes micropolarizer arrays

In this paper, we present the first in-depth analysis of the bandwidth tradeoffs, error performance, and noise resiliency of full-Stokes micropolarizer array (MPA) designs. By applying our Fourier domain tools that provide a systematic way for arranging information carriers and allocating bandwidth, we develop a number of new full-Stokes MPA layouts and compare them to the existing full-Stokes MPAs in the literature, all of which use 2 x 2 pixel unit cells to build the MPA. We compare the reconstruction accuracy afforded by these traditional designs with the generalized 2 x L family of MPAs, a 3 x 3 tiling, as well as a 2 x 2 x 3 layout that uses multiple snapshots and trades off temporal resolution for spatial resolution. Of those systems, the hybrid spatiotemporally modulated 2 x 2 x 3 MPA provisions the most bandwidth and provides the highest reconstruction accuracy, while the modified 2 x L family remains the best performing single-snapshot MPA. Additionally, we study the degradation of reconstruction accuracy under the presence of systematic error in MPA fabrication. We find that reducing the amount of correlated error is by far the largest factor in ensuring robust performance

Focal plane filter array engineering I : rectangular lattices

Focal planes arrays (FPA) measure values proportional to an integrated irradiance with little sensitivity to wavelength or polarization in the optical wavelength range. The measurement of spectral properties is often achieved via a spatially varying color filter array. Recently, spatially varying polarization filter arrays have been used to extract polarization information. Although measurement of color and polarization utilize separate physical methods, the underlying design and engineering methodology is linked. In this communication we derive a formalism which can be used to design any type of periodic filter array on a rectangular lattice. A complete system description can be obtained from the number of unit cells, the pixel shape, and the unit cell geometry. This formalism can be used to engineer the channel structure for any type of periodic tiling of a rectangular lattice for any type of optical filter array yielding irradiance measurements

Visual5.mp4

Evolution of the VATRR sampled system in the Poincaré sphere as the half wave plate is rotated over a 2 second time span