scholarly journals Easily Implemented Methods of Radiometric Corrections for Hyperspectral–UAV—Application to Guianese Equatorial Mudbanks Colonized by Pioneer Mangroves

2021 ◽  
Vol 13 (23) ◽  
pp. 4792
Author(s):  
Marion Jaud ◽  
Guillaume Sicot ◽  
Guillaume Brunier ◽  
Emma Michaud ◽  
Nicolas Le Dantec ◽  
...  
Keyword(s):  
French Guiana ◽  
Time Varying ◽  
Small Spatial Scale ◽  
Spectral Angle Mapper ◽  
Sediment Stabilization ◽  
Aerial Vehicle ◽  
In Situ Methods ◽  
Vehicle Platform ◽  
Hyperspectral Sensor

Hyper-DRELIO (Hyperspectral DRone for Environmental and LIttoral Observations) is a custom, mini-UAV (unmanned aerial vehicle) platform (<20 kg), equipped with a light push broom hyperspectral sensor combined with a navigation module measuring position and orientation. Because of the particularities of UAV surveys (low flight altitude, small spatial scale, and high resolution), dedicated pre-processing methods have to be developed when reconstructing hyperspectral imagery. This article presents light, easy-implementation, in situ methods, using only two Spectralon® and a field spectrometer, allowing performance of an initial calibration of the sensor in order to correct “vignetting effects” and a field standardization to convert digital numbers (DN) collected by the hyperspectral camera to reflectance, taking into account the time-varying illumination conditions. Radiometric corrections are applied to a subset of a dataset collected above mudflats colonized by pioneer mangroves in French Guiana. The efficiency of the radiometric corrections is assessed by comparing spectra from Hyper-DRELIO imagery to in situ spectrometer measurements above the intertidal benthic biofilm and mangroves. The shapes of the spectra were consistent, and the spectral angle mapper (SAM) distance was 0.039 above the benthic biofilm and 0.159 above the mangroves. These preliminary results provide new perspectives for quantifying and mapping the benthic biofilm and mangroves at the scale of the Guianese intertidal mudbanks system, given their importance in the coastal food webs, biogeochemical cycles, and the sediment stabilization.

LIGHTER-THAN-AIR (LTA) UNMANNED AERIAL SYSTEM (UAS) CARRIER CONCEPT FOR SURVAILLANCE AND DISASTER MANAGEMENT

2019 ◽  
Vol 3 ◽  
pp. 1255
Author(s):  
Ahmad Salahuddin Mohd Harithuddin ◽  
Mohd Fazri Sedan ◽  
Syaril Azrad Md Ali ◽  
Shattri Mansor ◽  
Hamid Reza Jifroudi ◽  
...  
Keyword(s):  
Unmanned Aerial Vehicles ◽  
Disaster Management ◽  
Unmanned Aerial Systems ◽  
Unmanned Aerial System ◽  
Border Control ◽  
Aerial Vehicles ◽  
Operational Safety ◽  
In Situ Methods ◽  
Aerial Systems

Unmanned aerial systems (UAS) has many advantages in the fields of SURVAILLANCE and disaster management compared to space-borne observation, manned missions and in situ methods. The reasons include cost effectiveness, operational safety, and mission efficiency. This has in turn underlined the importance of UAS technology and highlighted a growing need in a more robust and efficient unmanned aerial vehicles to serve specific needs in SURVAILLANCE and disaster management. This paper first gives an overview on the framework for SURVAILLANCE particularly in applications of border control and disaster management and lists several phases of SURVAILLANCE and service descriptions. Based on this overview and SURVAILLANCE phases descriptions, we show the areas and services in which UAS can have significant advantage over traditional methods.

scholarly journals Reference Measurements in Developing UAV Systems for Detecting Pests, Weeds, and Diseases

2021 ◽  
Vol 13 (7) ◽  
pp. 1238
Author(s):  
Jere Kaivosoja ◽  
Juho Hautsalo ◽  
Jaakko Heikkinen ◽  
Lea Hiltunen ◽  
Pentti Ruuttunen ◽  
...  
Keyword(s):  
Reference Data ◽  
Measurement Techniques ◽  
Synthetic Data ◽  
Ground Truth ◽  
Precision Farming ◽  
Aerial Imaging ◽  
Aerial Vehicle ◽  
Uav Images ◽  
Reference Measurements

The development of UAV (unmanned aerial vehicle) imaging technologies for precision farming applications is rapid, and new studies are published frequently. In cases where measurements are based on aerial imaging, there is the need to have ground truth or reference data in order to develop reliable applications. However, in several precision farming use cases such as pests, weeds, and diseases detection, the reference data can be subjective or relatively difficult to capture. Furthermore, the collection of reference data is usually laborious and time consuming. It also appears that it is difficult to develop generalisable solutions for these areas. This review studies previous research related to pests, weeds, and diseases detection and mapping using UAV imaging in the precision farming context, underpinning the applied reference measurement techniques. The majority of the reviewed studies utilised subjective visual observations of UAV images, and only a few applied in situ measurements. The conclusion of the review is that there is a lack of quantitative and repeatable reference data measurement solutions in the areas of mapping pests, weeds, and diseases. In addition, the results that the studies present should be reflected in the applied references. An option in the future approach could be the use of synthetic data as reference.

scholarly journals Monitoring of compliance with fuel sulfur content regulations through unmanned aerial vehicle (UAV) measurements of ship emissions

2019 ◽  
Vol 12 (11) ◽  
pp. 6113-6124 ◽  
Author(s):  
Fan Zhou ◽  
Shengda Pan ◽  
Wei Chen ◽  
Xunpeng Ni ◽  
Bowen An
Keyword(s):  
Unmanned Aerial Vehicle ◽  
Sulfur Content ◽  
Measurement System ◽  
Yangtze River Delta ◽  
Exhaust Gas ◽  
Ship Emissions ◽  
Chemical Examination ◽  
Airborne Measurements ◽  
Aerial Vehicle

Abstract. Air pollution from ship exhaust gas can be reduced by the establishment of emission control areas (ECAs). Efficient supervision of ship emissions is currently a major concern of maritime authorities. In this study, a measurement system for exhaust gas from ships based on an unmanned aerial vehicle (UAV) was designed and developed. Sensors were mounted on the UAV to measure the concentrations of SO2 and CO2 in order to calculate the fuel sulfur content (FSC) of ships. The Waigaoqiao port in the Yangtze River Delta, an ECA in China, was selected for monitoring compliance with FSC regulations. Unlike in situ or airborne measurements, the proposed measurement system could be used to determine the smoke plume at about 5 m from the funnel mouth of ships, thus providing a means for estimating the FSC of ships. In order to verify the accuracy of these measurements, fuel samples were collected at the same time and sent to the laboratory for chemical examination, and these two types of measurements were compared. After 23 comparative experiments, the results showed that, in general, the deviation of the estimated value for FSC was less than 0.03 % (m/m) at an FSC level ranging from 0.035 % (m/m) to 0.24 % (m/m). Hence, UAV measurements can be used for monitoring of ECAs for compliance with FSC regulations.

Material Reliability of Low-Temperature Boron Deposition for PureB Silicon Photodiode Fabrication

MRS Advances ◽  
2018 ◽  
Vol 3 (57-58) ◽  
pp. 3397-3402 ◽  
Author(s):  
L.K. Nanver ◽  
K. Lyon ◽  
X. Liu ◽  
J. Italiano ◽  
J. Huffman
Keyword(s):  
High Temperature ◽  
Layer Thickness ◽  
Vapor Deposition ◽  
Dark Current ◽  
Deposition Temperature ◽  
Chemical Vapor ◽  
Silicon Photodiode ◽  
In Situ Methods ◽  
Deposition Conditions

ABSTRACTThe chemical-vapor deposition conditions for the growth of pure boron (PureB) layers on silicon at temperatures as low as 400°C were investigated with the purpose of optimizing photodiodes fabricated with PureB anodes for minimal B-layer thickness, low dark current and chemical robustness. The B-deposition is performed in a commercially-available Si epitaxial reactor from a diborane precursor. In-situ methods commonly used to improve the cleanliness of the Si surface before deposition are tested for a deposition temperature of 450°C and PureB layer thickness of 3 nm. Specifically, high-temperature baking in hydrogen, and exposure to HCl are tested. Both material analysis and electrical diode characterization indicate that these extra cleaning steps degrade the properties of the PureB layer and the fabricated diodes.

In Situ Methods for Identifying the Stem Cell of the Normal and Cancerous Breast

2014 ◽  
pp. 151-182 ◽  
Author(s):  
Yanrong Su ◽  
Pedro J. Gutiérrez Diez ◽  
Julia Santucci-Pereira ◽  
Irma H. Russo ◽  
Jose Russo
Keyword(s):  
Stem Cell ◽  
In Situ Methods

scholarly journals DETERMINATION OF MECHANICAL PROPERTIES OF REPAIR MORTARS USING IN SITU METHODS UNDER DIFFERENT CURINGS

2020 ◽  
Vol 2 ◽  
pp. 3-18
Author(s):  
Ali Saberi Varzaneh ◽  
Mahmoud Naderi
Keyword(s):  
Mechanical Properties ◽  
Concrete Structures ◽  
High Impact ◽  
Physical Factors ◽  
High Confidence ◽  
In Situ Methods ◽  
Repair Mortars ◽  
Friction Transfer

Considering the differences between environmental conditions of concrete structures and laboratory conditions, it is important to determine the parameters of the materials at the site of the structure. One of these materials is cement-based repair mortars due to the damage of concrete structures that may arise due to chemical or physical factors, these structures are required to be repaired. For this reason, in this paper, to determine the strength of repair mortars of different ages and under different Curing, Situ methods "Friction-Transfer" and "Pull-off" were used and the relationships between the Flexural Compressive, Tensile and readings obtained from the above methods on cementations mortars are presented. Experiments were performed on mortars at ages 3, 7, 28, 42 and 90 days under the conditions of "waterlogging", "Curing Agent" and "releasing in the outdoor". The results show the high impact of the process on the Flexural Compressive, Tensile of the repair mortars and the results of the "Friction-Transfer" and "Pull-off" methods. Also, a high correlation coefficient was obtained between the mechanical properties of the mortars and the results of the above tests; it is possible to measure the mechanical properties of repair mortars in situ with high confidence and in situ

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