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

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

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 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.

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.

scholarly journals A Sensor Designed to Record Underwater Irradiance with Concern for a Shark’s Spectral Sensitivity

Biosensors ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 105
Author(s):  
A. Peter Klimley
Keyword(s):  
Spectral Response ◽  
High Light ◽  
Sensory Receptors ◽  
Response Curves ◽  
Low Light ◽  
Scalloped Hammerhead ◽  
Light Levels ◽  
Irradiation Energy ◽  
Underwater Irradiance ◽  
Peak Sensitivity

To ascertain how scalloped hammerhead sharks make nightly migrations to their feeding grounds as many as 20 km from their daytime abode, a seamount, a sensor was developed that measured irradiance intensity within the spectral range and sensitivity of the vision of the species. Could the sharks guide their movements by sensing the polarity of irradiation energy radiated from the sun or moon that penetrated into the oceanic depths? Two sensory receptors, cones and rods, are present in the retina of sharks to enable them to see both during daytime and nighttime. The peak sensitivity of the cones is red-shifted due to the presence of these wavelengths during the former period, while their response is linear under the range of the high light levels also present at this time; the peak sensitivity of rods is blue-shifted due to the presence of these wavelengths during dawn, dusk, and nighttime and is linear over the complementary range of low light levels. Spectral response curves for these two receptors were determined for sharks, and an attempt was made to match those of the sensors to the shark’s wavelength perception. The first sensor was matched to the photopic range using a photocell covered with a red-shifted gel filter; the second was matched to the scotopic range using a blue-shifted gel filter.

Diurnal Changes in Structure and Function of the Compound Eye of Ligia Exotica (Crustacea, Isopoda)

1986 ◽  
Vol 123 (1) ◽  
pp. 1-26
Author(s):  
TAKAHIKO HARIYAMA ◽  
V. BENNO MEYER-ROCHOW ◽  
EISUKE EGUCHI
Keyword(s):  
Compound Eye ◽  
Spectral Response ◽  
Green Light ◽  
Diurnal Changes ◽  
Response Curves ◽  
Continuous Darkness ◽  
Closed Type ◽  
And Function ◽  
Two Peaks ◽  
Irregular Arrangement

The ultrastructure of the retinula cells of Ligia exotica changes diurnally and in response to light/dark adaptation. At the low phase of electroretinogram (ERG) amplitude (at noon), the arrangement of microvilli is ordered and the rhabdom is of the open type. An irregular arrangement of microvilli appears at the high phase of ERG amplitude (at midnight), when the rhabdom is of the closed type. The pigment granules disperse at midnight and assemble at noon. A centrally positioned, spikeproducing eccentric cell is present in each ommatidium. Spectral response curves based on ERG measurements have two maxima, one to light of 383 nm wavelength, the other at around 520 nm. These two peaks represent the two classes of receptor cells identified by intracellular recordings. The ERG responses to light of 383 nm and 520 nm wavelengths display a diurnal rhythmicity, being high at night and low during the day. However, the responses to green light are more strongly affected than those to ultraviolet light. Consequently, the eye displays a relatively higher ultraviolet-sensitivity during the day, whereas at night sensitivity to green light is increased. This behaviour, which persists in continuous darkness, suggests that an endogenous mechanism is involved in bringing about the observed diurnal morphological and physiological changes in the compound eye of Ligia exotica.

Quantitative relations between color-opponent response of horizontal cells and action spectra of cones

1983 ◽  
Vol 49 (4) ◽  
pp. 961-975 ◽  
Author(s):  
D. A. Burkhardt ◽  
G. Hassin
Keyword(s):  
Spectral Response ◽  
Linear Range ◽  
Response Amplitude ◽  
Horizontal Cells ◽  
Good Precision ◽  
C Cells ◽  
Response Curves ◽  
Action Spectra ◽  
Long Wave ◽  
Simple Summation

1. Relations between cones and chromatic-type horizontal cells (C-cells) were investigated by intracellular recording in the retina of the walleye (Stizostedion vitreum). 2. The retina contains two classes of cones, midwave (M) and long wave (L). Their action spectra have maximum sensitivity at 533 and 605 nm, respectively, and have been measured with good precision from 400 to 750 nm. 3. C-cells generate relatively sustained depolarizing and hyperpolarizing responses to deep red (680 nm) and green (530 nm) test flashes, respectively, but prominent on and off transients are evoked by intermediate wavelengths. To minimize these temporal interactions, quantitative analysis was restricted to measurements of the apparent steady-state response amplitude. 4. Response amplitude was linearly related to flash intensity for responses that did not exceed 20% of their respective maxima. This is called the linear range. At higher levels, the nonlinear region of the Naka-Rushton relation holds approximately if input is largely confined to the hyperpolarizing or depolarizing mechanism. 5. Tests with red/green mixture flashes show that the hyperpolarizing and depolarizing inputs interact by simple summation for responses in the linear range. At higher levels, the interaction is complex. 6. Spectral-response curves (response amplitude versus wavelength for flashes of equal photon level) were determined for 16 C-cells in the linear range. The exact form of these curves varied considerably from cell to cell, reflecting differences in the relative strength of the hyperpolarizing and depolarizing mechanisms. 7. The spectral-response curves were analyzed by a simple linear model based on the action spectra of the L and M cones. Measured and predicted spectral-response curves agree closely. The only free parameter in the analysis is a scaling factor that specifies the strength of the L cone input relative to the M cone input. 8. Triphasic spectral-response curves, as predicted by the model, were found in the sauger (Stizostedion canadense). These C-cells have short-wavelength responses due to input from long-wave cones, resemble certain triphasic cells in primate retina, and differ sharply from other triphasic C-cells found in other fish retinas. 9. Although the precise synaptic mechanisms must still be identified, the present results show that the functional information transfer from cones to C-cells in the linear range can be closely approximated by simple operations of scaling, sign inversion, and simple summation. The C-cell thus effectively subtracts one cone action spectrum from the other and displays the difference in the form of the spectral-response curve.

scholarly journals Light Quality Effect on Corn Growth as Influenced by Weed Species and Nitrogen Rate

2016 ◽  
Vol 9 (1) ◽  
pp. 15 ◽  
Author(s):  
Thomas R. Butts ◽  
Joshua J. Miller ◽  
J. Derek Pruitt ◽  
Bruno C. Vieira ◽  
Maxwel C. Oliveira ◽  
...  
Keyword(s):  
Weed Management ◽  
Light Quality ◽  
Spectral Response ◽  
Shoot Biomass ◽  
Limiting Factor ◽  
Weed Species ◽  
Fibrous Root ◽  
Response Curves ◽  
Early Season ◽  
Greenhouse Study

<p>Corn-weed competition has often been characterized as the competition for limited resources such as light quantity, water, and nutrients. However, growing evidence suggests that light quality, specifically the red:far red ratio (R:FR), is a crucial component to corn-weed interactions. Additionally, a reduction in the R:FR has shown to down-regulate plant genes similarly to a nitrogen (N) deficient environment. A greenhouse study was conducted to evaluate the effect of N stress and R:FR from common waterhemp, velvetleaf, and volunteer corn on corn growth and development. The R:FR for all three weed species tended to be similar but lower than a weed-free treatment. However, observations from the spectral response curves demonstrated significant changes in the patterns of light reflected from each weed species. In the N-sufficient environment, early-season (V5 corn growth stage) R:FR from all three weed species reduced corn height, leaf chlorophyll content, and shoot biomass while increasing fibrous root biomass. However, in the N-deficient environment, no effects were observed on corn growth from changes in light quality, indicating N stress was a greater limiting factor. These results highlight the importance of the critical weed-free period and the need for proper early-season weed management.</p>

Sign in / Sign up

Export Citation Format

Share Document