Electrophysiological response of Dendroctonus pseudotsugae and Ips paraconfusus (Coleoptera: Scolytidae) to selected wavelength regions of the visible spectrum

1982 ◽  
Vol 60 (9) ◽  
pp. 2180-2189 ◽  
Author(s):  
L. J. Groberman ◽  
J. H. Borden
Keyword(s):  
Fiber Optics ◽  
Spatial Information ◽  
Spectral Response ◽  
Visible Spectrum ◽  
Ips Paraconfusus ◽  
Compound Eyes ◽  
Response Curves ◽  
Dendroctonus Pseudotsugae ◽  
Electrophysiological Response ◽  
Sensitivity Curves

Electroretinograms (ERGs) were recorded from the compound eyes of both sexes of Dendroctonus pseudotsugae Hopkins and Ips paraconfusus (Lanier). Light stimuli between 400 and 650 nm were delivered to the compound eyes through a monochromator connected to a fiber-optics and lens light-delivery system. Stimulus intensity was regulated with neutral density filters. The averaged spectral response curves were similar for both species and sexes. The spectral sensitivity curves disclosed two sensitivity maxima, one in the blue region (450 nm) and one in the green region (510 to 530 nm). These correspond well with behavioural data on scolytids and with response peaks reported in other insects and provide evidence that the scolytid visual system consists of two receptor types. The blue receptors are probably used in navigation during the initial stages of the dispersal flight and the green receptors for the detection of spatial information during host selection.

scholarly journals Characterizing Changes in Soybean Spectral Response Curves with Breeding Advancements

Crop Science ◽  
2014 ◽  
Vol 54 (4) ◽  
pp. 1585-1597 ◽  
Author(s):  
Brent S. Christenson ◽  
William T. Schapaugh ◽  
Nan An ◽  
Kevin P. Price ◽  
Allan K. Fritz
Keyword(s):  
Spectral Response ◽  
Response Curves

Organic photodetector with spectral response tunable across the visible spectrum by means of internal optical microcavity

2009 ◽  
Vol 10 (6) ◽  
pp. 1152-1157 ◽  
Author(s):  
Kwang Hyup An ◽  
Brendan O’Connor ◽  
Kevin P. Pipe ◽  
Max Shtein
Keyword(s):  
Spectral Response ◽  
Visible Spectrum ◽  
Optical Microcavity ◽  
Organic Photodetector

Method to validate relative spectral response curves

1998 ◽  
Author(s):  
John E. Hubbs ◽  
John P. Garcia ◽  
Eustace L. Dereniak
Keyword(s):  
Spectral Response ◽  
Response Curves

The Optical Properties of Plasma-Deposited SiO2 and Si3N4 Bragg Reflectors in the Spectral Range from 1.8 to 3.0 eV

1992 ◽  
Vol 281 ◽  
Author(s):  
D. J. Stephens ◽  
S. S. He ◽  
G. Lucovsky ◽  
H. Mkkelsen ◽  
K. Leo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Periodic Structures ◽  
Spectral Response ◽  
Chemical Vapor ◽  
Visible Spectrum ◽  
Bragg Reflectors ◽  
Spectral Bands ◽  
Entire Visible Spectrum ◽  
Optical Behavior ◽  
Constituent Layer

ABSTRACTWe have prepared 19-layer Si3N4:SiO2/…‥Si3N4:SiO2/Si3N4 (HL/HL/…HL/H), Bragg reflectors by remote plasma-enhanced chemical-vapor deposition, and have adjusted the constituent layer thicknesses to generate highly reflecting films over the entire visible spectrum from approximately 1.8 eV (∼690 nm) to 3.0 eV (∼410 nm). Peak values of the reflectance, in spectral bands with half-widths of ∼0.4 to 0.5 eV, are in the range of 96 to 98 %. The spectral response functions of these stacks exhibit departures from the optical behavior as calculated for exactly periodic structures with λ/4 layer thicknesses, and can be accounted for by taking into account: i) dispersion and absorption in the optical properties of the constituent layers; and ii) departures from the idealized and constant layer thicknessses.

scholarly journals NATIONAL GUIDELINES FOR DIGITAL CAMERA SYSTEMS CERTIFICATION

2016 ◽  
Vol XLI-B1 ◽  
pp. 179-184
Author(s):  
Yaron Yaron ◽  
Eran Keinan ◽  
Moshe Benhamu ◽  
Ronen Regev ◽  
Garry Zalmanzon
Keyword(s):  
Laser Scanning ◽  
Spectral Response ◽  
Spectral Characteristics ◽  
Digital Camera ◽  
Director General ◽  
National Guidelines ◽  
Response Curves ◽  
High Quality ◽  
Camera Systems ◽  
Imaging Sensors

Digital camera systems are a key component in the production of reliable, geometrically accurate, high-resolution geospatial products. These systems have replaced film imaging in photogrammetric data capturing. Today, we see a proliferation of imaging sensors collecting photographs in different ground resolutions, spectral bands, swath sizes, radiometric characteristics, accuracies and carried on different mobile platforms. In addition, these imaging sensors are combined with navigational tools (such as GPS and IMU), active sensors such as laser scanning and powerful processing tools to obtain high quality geospatial products. The quality (accuracy, completeness, consistency, etc.) of these geospatial products is based on the use of calibrated, high-quality digital camera systems. <br><br> The new survey regulations of the state of Israel specify the quality requirements for each geospatial product including: maps at different scales and for different purposes, elevation models, orthophotographs, three-dimensional models at different levels of details (LOD) and more. In addition, the regulations require that digital camera systems used for mapping purposes should be certified using a rigorous mapping systems certification and validation process which is specified in the Director General Instructions. The Director General Instructions for digital camera systems certification specify a two-step process as follows: <br><br> 1. Theoretical analysis of system components that includes: study of the accuracy of each component and an integrative error propagation evaluation, examination of the radiometric and spectral response curves for the imaging sensors, the calibration requirements, and the working procedures. <br><br> 2. Empirical study of the digital mapping system that examines a typical project (product scale, flight height, number and configuration of ground control points and process). The study examine all the aspects of the final product including; its accuracy, the product pixels size on the ground (spatial resolution), its completeness (missing pixels and striping affect), its radiometric properties (e.g., relative edge response) and its spectral characteristics (e.g., histogram spread, bands misalignment). <br><br> This methodology was tested on a number of medium to large format digital cameras. The certification process is a basic stage in the mapping chain in Israel. This article provides the details of the Director General Instructions for digital camera systems certification, the methodology for certification and the tests that were carried out.

scholarly journals Spatial information capacity of compound eyes

1977 ◽  
Vol 116 (2) ◽  
pp. 183-207 ◽  
Author(s):  
Allan W. Snyder ◽  
Doekele G. Stavenga ◽  
Simon B. Laughlin
Keyword(s):  
Spatial Information ◽  
Information Capacity ◽  
Compound Eyes

New Accessory for Characterizing Optical Fibers with an FT-IR Spectrometer

1994 ◽  
Vol 48 (7) ◽  
pp. 852-856 ◽  
Author(s):  
S. Lowry ◽  
T. May ◽  
A. Bornstein ◽  
Y. Weissman ◽  
R. Harman ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Optical Properties ◽  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Spectral Response ◽  
Spectral Transmission ◽  
Acceptance Angle ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

An accessory has been designed for FT-IR spectroscopy that can be used to measure the optical properties of fiber-optic cables or serve as an interface for remote sensing probes that use fiber optics. This accessory utilizes compound parabolic concentrators (CPCs) to focus the energy from the spectrometer into the optical fiber and to also refocus the energy returning to the spectrometer onto the detector. The design was optimized for the high acceptance angle of chalcogenide mid-IR fibers. However, the use of nonimaging concentrators yields an all-reflecting system that can be used to characterize fibers with different spectral transmission ranges. This accessory has been used to investigate the spectral response, cladding effects, and impurities in various optical fibers.

Improved Concept for Nipiin and PIIIN Color Sensitive Two-Terminal Devices with High Linearity

1997 ◽  
Vol 467 ◽  
Author(s):  
D. Knipp ◽  
H. Stiebig ◽  
J. Fölsch ◽  
R. Carius ◽  
H. Wagner
Keyword(s):  
Light Intensity ◽  
Dynamic Range ◽  
Layer Structure ◽  
Spectral Response ◽  
Incident Light ◽  
High Dynamic Range ◽  
Optical Signal ◽  
Optimized Design ◽  
Defect States ◽  
Response Curves

ABSTRACTThe detection of the fundamental components of the visible light (blue, green, red) is achieved with two terminal photo diodes based on amorphous silicon. By changing the bias voltage the preferential carrier collection region is shifted which leads to a color sensitivity. In order to obtain a high dynamic range, independent voltage controlled spectral response curves as well as a linear response of the photocurrent on the incident light intensity the μτ-product and the bandgap in the device have to be specially designed to deconvolute the optical signal and generate an RGB-signal. Since the light intensity can strongly influence the spectral sensitivity by recharging of defect states, an optimized design of the multi-layer structure is necessary. Therefore, an improved concept for the design of nipiin- and piiin-detectors is presented which results in a good suppression of these non-linearities. Our concept is based on a decreasing bandgap profile from the front to the back contact and an increasing μτ-product of the individual i-layers in direction of the p-layer.

Center-surround organization in bipolar cells: Symmetry for opposing contrasts

2003 ◽  
Vol 20 (1) ◽  
pp. 1-10 ◽  
Author(s):  
PATRICK K. FAHEY ◽  
DWIGHT A. BURKHARDT
Keyword(s):  
Bipolar Cell ◽  
Spatial Information ◽  
Horizontal Cell ◽  
Positive Contrast ◽  
Bipolar Cells ◽  
Ambystoma Tigrinum ◽  
Maximal Response ◽  
Response Curves ◽  
Contrast Polarity ◽  
Contrast Gain

Intracellular recordings were obtained from 73 cone-driven bipolar cells in the light-adapted retina of the tiger salamander (Ambystoma tigrinum). Responses to flashes of negative and positive contrast for centered spots and concentric annuli of optimum spatial dimensions were analyzed as a function of contrast magnitude. For both depolarizing and hyperpolarizing bipolar cells, it was found that remarkably similar responses were observed for the center and surround when comparisons were made between responses of the same response polarity and thus, responses to opposite contrast polarity. Thus, spatial information and contrast polarity appear to be rather strongly confounded in many bipolar cells. As a rule, the form of the contrast/response curves for center and surround approximated mirror images of each other. Contrast gain and C50 (the contrast required for half-maximal response) were quantitatively similar for center and surround when comparisons were made for responses of the same response polarity. The average contrast gain of the bipolar cell surround was 3–5 times higher than that measured for horizontal cells. Contrast/latency measurements and interactions between flashed spots and annuli showed that the surround response is delayed by 20–80 ms with respect to that of the receptive-field center. Cones showed no evidence for center-surround antagonism while for bipolar cells, the average strength of the surround ranged from about 50% to 155% of the center, depending on the test and response polarity. The results of experiments on the effects of APB (100 μM) on depolarizing bipolar cells suggest that the relative contribution of the feedback pathway (horizontal cell to cones) and the feedforward pathway (horizontal cell to bipolar cell) to the bipolar surround varies in a distributed manner across the bipolar cell population.

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