scholarly journals Use of Near-Infrared video for Localizing Nitrogen Stress in Peach Orchards

1992 ◽  
Vol 2 (2) ◽  
pp. 224-227
Author(s):  
G.W. Stutte ◽  
C.A. Stutte
Keyword(s):  
Spatial Variability ◽  
Near Infrared ◽  
Broad Band ◽  
Canopy Reflectance ◽  
Pixel Intensity ◽  
Cumulative Stress ◽  
Infrared Video ◽  
Leaf N Content ◽  
The Relationship ◽  
Peach Orchard

Computer analysis of airborne, broad-band, near-infrared (NIR, 710 to 1100 nm) video imagery of peach tree canopies was used to determine spatial variability of cumulative stress in two peach orchards. A significant quadratic correlation was found between leaf-N content and the normalized mean pixel intensity (MPI) of the digital imagery of NIR canopy reflectance. This correlation was used to establish MPI estimates of N-stressed trees in the orchard. The relationship was used to localize site-specific spatial variability in a commercial peach orchard. The underlying soil type was found to be closely associated with the spatial variability in NIR imagery in the commercial peach orchard. Assessing spatial variability in the orchard with NIR video permits early localization of potentially low productivity regions within an orchard.

scholarly journals CLASSIFICATION OF STRESS-INDUCED SPATIAL VARIABILITY IN NEAR-INFRARED CANOPY REFLECTANCE.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1136b-1136
Author(s):  
Gary W. Stutte
Keyword(s):  
Spatial Variability ◽  
Near Infrared ◽  
Video Camera ◽  
Canopy Reflectance ◽  
Band Pass Filter ◽  
Image Capture ◽  
Pass Filter ◽  
Digital Video Camera ◽  
Custom Made ◽  
Analysis System

A digital video camera (Panasonic Industrial Co., Secaucus, NJ) with a 1.7 cm charged coupled device detector (574 (h) × 499 (v) pixel elements) was modified with a custom made FRF-700 band pass filter to visualize canopy reflectance in the near-infrared (NIR) from 700 to 1100 nm. Images of canopy reflectance under a range of environmental stresses were obtained from peach and apple trees under greenhouse and field conditions. Individual video frames were digitized with Image Capture and Analysis System (Agri Imaging Systems, Inc., Fayetteville, AR). Image contrast was increased with digital equalization and filtering before classification into one of five stress levels. There was a high correlation (r2 > 0.8) between leaf stress and canopy reflectance in both apple and peach at distances < 5 meters. Spatial variability in stress-induced NIR reflectance could be detected and classified at vertical distances from 150 to 500 M. Analysis of vertical imagery revealed sections of the orchard which were most susceptible to environmental stress.

Ab Initio Two-sites Occupancy and Broadband Near-Infrared Emission of Cr3+ in Li2MgZrO4

2021 ◽  
Author(s):  
Xue Zhou ◽  
Jinmeng Xiang ◽  
Jiming Zheng ◽  
Xiaoqi Zhao ◽  
Hao Suo ◽  
...  
Keyword(s):  
Plant Growth ◽  
Ab Initio ◽  
Light Source ◽  
Near Infrared ◽  
Broad Band ◽  
Infrared Emission ◽  
Night Vision ◽  
Light Emitting ◽  
Non Destructive ◽  
Near Infrared Emission

Near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) light source have great potential in non-destructive detection, promoting plant growth and night vision applications, while the discovery of a broad-band NIR phosphor still...

scholarly journals Recent advances in applications of multimodal ultrasound-guided photoacoustic imaging technology

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Shanshan Wang ◽  
Yunfeng Zhao ◽  
Ye Xu
Keyword(s):  
Near Infrared ◽  
Photoacoustic Imaging ◽  
Imaging Techniques ◽  
Color Doppler ◽  
Power Doppler ◽  
Infrared Region ◽  
Detection Methods ◽  
Imaging Mode ◽  
Nonlinear Imaging ◽  
The Relationship

Abstract Photoacoustic imaging (PAI) is often performed simultaneously with ultrasound imaging and can provide functional and cellular information regarding the tissues in the anatomical markers of the imaging. This paper describes in detail the basic principles of photoacoustic/ultrasound (PA/US) imaging and its application in recent years. It includes near-infrared-region PA, photothermal, photodynamic, and multimode imaging techniques. Particular attention is given to the relationship between PAI and ultrasonic imaging; the latest high-frequency PA/US imaging of small animals, which involves not only B-mode, but also color Doppler mode, power Doppler mode, and nonlinear imaging mode; the ultrasonic model combined with PAI, including the formation of multimodal imaging; the preclinical imaging methods; and the most effective detection methods for clinical research for the future.

Broad band optical band-reject filters in near-infrared regime utilizing bilayer Ag metasurface

2017 ◽  
Vol 121 (15) ◽  
pp. 153105 ◽  
Author(s):  
X. L. Hu ◽  
L. B. Sun ◽  
Q. J. Wu ◽  
L. S. Wang ◽  
S. A. Bai ◽  
...  
Keyword(s):  
Near Infrared ◽  
Broad Band

scholarly journals Final design and on-sky testing of the iLocater SX acquisition camera: broad-band single-mode fibre coupling

2020 ◽  
Vol 501 (2) ◽  
pp. 2250-2267
Author(s):  
J Crass ◽  
A Bechter ◽  
B Sands ◽  
D King ◽  
R Ketterer ◽  
...  
Keyword(s):  
Adaptive Optics ◽  
Near Infrared ◽  
Broad Band ◽  
Single Mode ◽  
Injection System ◽  
Single Mode Fibre ◽  
Astronomical Instruments ◽  
Final Design ◽  
Camera Design ◽  
And Performance

ABSTRACT Enabling efficient injection of light into single-mode fibres (SMFs) is a key requirement in realizing diffraction-limited astronomical spectroscopy on ground-based telescopes. SMF-fed spectrographs, facilitated by the use of adaptive optics (AO), offer distinct advantages over comparable seeing-limited designs, including higher spectral resolution within a compact and stable instrument volume, and a telescope independent spectrograph design. iLocater is an extremely precise radial velocity (EPRV) spectrograph being built for the Large Binocular Telescope (LBT). We have designed and built the front-end fibre injection system, or acquisition camera, for the SX (left) primary mirror of the LBT. The instrument was installed in 2019 and underwent on-sky commissioning and performance assessment. In this paper, we present the instrument requirements, acquisition camera design, as well as results from first-light measurements. Broad-band SMF coupling in excess of 35 per cent (absolute) in the near-infrared (0.97–1.31 ${\mu {\rm m}}$) was achieved across a range of target magnitudes, spectral types, and observing conditions. Successful demonstration of on-sky performance represents both a major milestone in the development of iLocater and in making efficient ground-based SMF-fed astronomical instruments a reality.

A Comparison of Near-Infrared Imaging and Computerized Tomography Scan for Detecting Maxillary Sinusitis

2021 ◽  
pp. 000348942110606
Author(s):  
Mehdi Abouzari ◽  
Brooke Sarna ◽  
Joon You ◽  
Adwight Risbud ◽  
Kotaro Tsutsumi ◽  
...  
Keyword(s):  
Maxillary Sinus ◽  
Computerized Tomography ◽  
Sensitivity And Specificity ◽  
Near Infrared ◽  
Maxillary Sinusitis ◽  
Tertiary Care ◽  
Pixel Intensity ◽  
Sinus Disease ◽  
Nir Imaging ◽  
Average Pixel Intensity

Objective: To investigate the use of near-infrared (NIR) imaging as a tool for outpatient clinicians to quickly and accurately assess for maxillary sinusitis and to characterize its accuracy compared to computerized tomography (CT) scan. Methods: In a prospective investigational study, NIR and CT images from 65 patients who presented to a tertiary care rhinology clinic were compared to determine the sensitivity and specificity of NIR as an imaging modality. Results: The sensitivity and specificity of NIR imaging in distinguishing normal versus maxillary sinus disease was found to be 90% and 84%, normal versus mild maxillary sinus disease to be 76% and 91%, and mild versus severe maxillary sinus disease to be 96% and 81%, respectively. The average pixel intensity was also calculated and compared to the modified Lund-Mackay scores from CT scans to assess the ability of NIR imaging to stratify the severity of maxillary sinus disease. Average pixel intensity over a region of interest was significantly different ( P < .001) between normal, mild, and severe disease, as well as when comparing normal versus mild ( P < .001, 95% CI 42.22-105.39), normal versus severe ( P < .001, 95% CI 119.43-174.14), and mild versus severe ( P < .001, 95% CI 41.39-104.56) maxillary sinus disease. Conclusion: Based on this data, NIR shows promise as a tool for identifying patients with potential maxillary sinus disease as well as providing information on severity of disease that may guide administration of appropriate treatments.

How landscape and climate affect the spatial variability of the Italian rainfall extremes? Some initial clues based on I2-RED

2021 ◽  
Author(s):  
Paola Mazzoglio ◽  
Ilaria Butera ◽  
Pierluigi Claps
Keyword(s):  
Spatial Variability ◽  
Linear Regression Analysis ◽  
Alpine Region ◽  
Annual Rainfall ◽  
Mean Values ◽  
Rainfall Extremes ◽  
Geomorphological Parameters ◽  
The Mean ◽  
The Relationship ◽  
Italian Territory

&lt;p&gt;The intensity and the spatial distribution of precipitation depths are known to be highly dependent on relief and geomorphological parameters. Complex environments like mountainous regions are prone to intense and frequent precipitation events, especially if located near the coastline. Although the link between the mean annual rainfall and geomorphological parameters has received substantial attention, few literature studies investigate the relationship between the sub-daily maximum annual rainfall depth and geographical or morphological landscape features.&lt;br&gt;In this study, the mean of the rainfall extremes in Italy, recently revised in the so-called I&lt;sup&gt;2&lt;/sup&gt;-RED dataset, are investigated in their spatial variability in comparison with some landscape and also some broad climatic characteristics. The database includes all sub-daily rainfall extremes recorded in Italy from 1916 until 2019 and this analysis considers their mean values (from 1 to 24 hours) in stations with at least 10 years of records, involving more than 3700 stations.&lt;br&gt;The geo-morpho-climatic factors considered range from latitude, longitude and minimum distance from the coastline on the geographic side, to elevation, slope, openness and obstruction morphological indices, and also include an often-neglected robust climatological information, as the local mean annual rainfall.&lt;br&gt;Obtained results highlight that the relationship between the annual maximum rainfall depths and the hydro-geomorphological parameters is not univocal over the entire Italian territory and over different time intervals. Considering the whole of Italy, the highest correlation is reached between the mean values of the 24-hours records and the mean annual precipitation (correlation coefficient greater than 0.75). This predominance remains also in sub-areas of the Italian territory (i.e., the Alpine region, the Apennines or the coastal areas) but correlation decreases as the time interval decreases, except for the Alpine region (0.73 for the 1-hour maximum). The other geomorphological parameters seem to act in conjunction, making it difficult to evaluate, with a simple linear regression analysis, their impact. As an example, the absolute value of the correlation coefficient between the elevation and the 1-hour extremes is greater than 0.35 for the Italian and the Alpine regions, while for the 24-hours interval it is greater than 0.35 over the coastal areas.&lt;br&gt;To further investigate the spatial variability of the relationship between rainfall and elevation, a spatial linear regression analysis has been undertaken. Local linear relationships have been fitted in circles centered on any of the 0.5-km size pixels in Italy, with 1 to 30 km radius and at least 5 stations included. Results indicate the need of more comprehensive terrain analysis to better understand the causes of local increasing or decreasing relations, poorly described in the available literature.&lt;/p&gt;

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