scholarly journals Estimation of NDVI with visible images (RGB) obtained with drones

2020 ◽  
Vol 9 (6) ◽  
pp. 407
Author(s):  
Josiclêda Domiciano Galvíncio ◽  
Carine Rosa Naue
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Health Conditions ◽  
Radiometric Calibration ◽  
Quality Of Data ◽  
Data Products ◽  
Visible Images ◽  
Calibration Equations

The NDVI (Normalized Difference Vegetation Index) is a vegetation index widely used to evaluate the health conditions of vegetation, whether preserved or derived from anthropic actions, such as agriculture. NDVI's estimation with drones is still quite precarious as it requires different studies to assess their accuracy. The aim of this study is to evaluate the NDVI estimate obtained with images of the visible attention to radiometric calibrations. Radiometric calibration equations that were widely disseminated for the use of Landsat 5 satellite were used. These equations were used to calibrate drone images. The results showed that the calibrations raised the level of accuracy of NDVI estimates with drone images. It is concluded that it is of paramount importance the radiometric calibration of the images obtained with drones so that they allow more accurate estimates, such as NDVI. The use of drone products to estimate NDVI is quite promising. But it is necessary to study more robust radiometric calibration procedures, increasing the quality of data products from drones and making it more comparable between sites, sensors, and schedules.Estimativa do NDVI com imagens do visível (RGB) obtidas com drones R E S U M OO NDVI (Normalized Difference Vegetation Index) é um índice de vegetação muito utilizado para avaliação das condições de saúde da vegetação, seja ela preservada ou advinda das ações antrópicas, como por exemplo, agricultura. A estimativa do NDVI com drones ainda é bastante precária uma vez que necessita de diferentes estudos para avaliar a precisão deles. O objetivo deste estudo é avaliar a estimativa do NDVI obtidas com imagens do visível atentando para as calibrações radiométricas. Foram utilizadas equações de calibração radiométricas bastantes difundidas para uso do satélite Landsat 5. Essas equações foram utilizadas para calibração de imagens de drones. Os resultados mostraram que as calibrações elevaram o nível de acurácia das estimativas do NDVI com imagens de drones. Conclui-se que é de suma importância a calibração radiométrica das imagens obtidas com drones para que elas possibilitem estimativas mais precisas, como por exemplo o NDVI. O uso de produtos de drones para estimativa de NDVI é bastante promissor. Mas, se faz necessário o estudo de mais procedimentos robustos de calibração radiométrica, aumentando a qualidade dos produtos de dados advindos de drones e tornando mais comparáveis entre sites, sensores e horários.Palavras-chave: Calibração radiométrica, condições ambientais, monitoramento.

scholarly journals Influence of the use and the land cover of the catchment in the water quality of the semiarid tropical reservoirs

2018 ◽  
Vol 7 (7) ◽  
pp. 389
Author(s):  
Herika Cavalcante ◽  
Patrícia Silva Cruz ◽  
Leandro Gomes Viana ◽  
Daniely De Lucena Silva ◽  
José Etham De Lucena Barbosa
Keyword(s):  
Water Quality ◽  
Supervised Classification ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Landsat 8 ◽  
Dissolved Phosphorus ◽  
Sparse Vegetation ◽  
Tropical Reservoirs

The aim of this study was to evaluate some parameters of water quality of semiarid reservoirs under different uses and occupation of the catchment’s soil. For this, the reservoirs Acauã and Boqueirão, belonging to the Paraíba do Norte river watershed and Middle and Upper course sub catchments, respectively, were studied. For this, water samples were collected in August, September and October 2016. From these samples, total and dissolved phosphorus, nitrate, nitrite, ammonia, chlorophyll, dissolved and suspended solids were analyzed. In addition, images of the Landsat 8 satellite were acquired for the calculation of the Normalized Difference Vegetation Index (NDVI), and for the supervised classification of the use and occupation of the sub catchments. Thus, it was observed that, in general, the Acauã reservoir presented values of phosphorus and nitrogen and solids larger than the Boqueirão reservoir, due to the greater urban area, even though it had a smaller total area of the basin. Both reservoirs presented low vegetation rates and high areas of sparse vegetation and exposed soil, increasing the propensity to soil erosion and the transport of nutrients from the basin to the reservoirs, making water quality worse or impossible.

scholarly journals Green open space analysis in West Binjai, North Sumatra

2021 ◽  
Vol 886 (1) ◽  
pp. 012095
Author(s):  
A Zaitunah ◽  
Samsuri ◽  
Rojula ◽  
A. Susilowati ◽  
D. Elfiati ◽  
...  
Keyword(s):  
Open Space ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Dense Medium ◽  
Vegetation Density ◽  
Open Spaces ◽  
River Bank ◽  
Dense Class ◽  
North Sumatra

Abstract West Binjai is a sub-district located in Binjai City, North Sumatra. Green Open Space is also part of the Binjai city’s planning scheme which has many benefits for the community and the environment. This research used Normalized Difference Vegetation Index (NDVI) analysis and NDVI value classification results in the distribution of vegetation density. Analysis of changes in vegetation density was carried out between 2015 and 2020 in West Binjai. The largest change in the area of vegetation density classes in the West Binjai between 2015 and 2020 was the increase in the area of the high dense class to 19.13%. The sub-district has green open spaces in the form of sub-district parks, public cemeteries, road green lane, river bank and private green open spaces. These green open spaces were in the low dense, medium, dense and high dense classes. There is a need for rearrangement of green open spaces, especially those within low dense class. Replanting trees are also essential to increase the quality of the green area. Improving the quality of green space will lead to the enhancement of quality of environment.

scholarly journals Normalized Difference Vegetation Index as an Estimator for Abundance and Quality of Avian Herbivore Forage in Arctic Alaska

2017 ◽  
Vol 9 (12) ◽  
pp. 1234 ◽  
Author(s):  
Kyle Hogrefe ◽  
Vijay Patil ◽  
Daniel Ruthrauff ◽  
Brandt Meixell ◽  
Michael Budde ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Arctic Alaska

scholarly journals A NOVEL IHS-GA FUSION METHOD BASED ON ENHANCEMENT VEGETATED AREA

2015 ◽  
Vol XL-1-W5 ◽  
pp. 543-548
Author(s):  
S. Niazi ◽  
M. Mokhtarzade ◽  
F. Saeedzadeh
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Data Sets ◽  
Panchromatic Image ◽  
Fused Image ◽  
Novel Method ◽  
Intensity Image ◽  
Imaging Sensors ◽  
Gray Values

Pan sharpening methods aim to produce a more informative image containing the positive aspects of both source images. However, the pan sharpening process usually introduces some spectral and spatial distortions in the resulting fused image. The amount of these distortions varies highly depending on the pan sharpening technique as well as the type of data. Among the existing pan sharpening methods, the Intensity-Hue-Saturation (IHS) technique is the most widely used for its efficiency and high spatial resolution. When the IHS method is used for IKONOS or QuickBird imagery, there is a significant color distortion which is mainly due to the wavelengths range of the panchromatic image. Regarding the fact that in the green vegetated regions panchromatic gray values are much larger than the gray values of intensity image. A novel method is proposed which spatially adjusts the intensity image in vegetated areas. To do so the normalized difference vegetation index (NDVI) is used to identify vegetation areas where the green band is enhanced according to the red and NIR bands. In this way an intensity image is obtained in which the gray values are comparable to the panchromatic image. Beside the genetic optimization algorithm is used to find the optimum weight parameters in order to gain the best intensity image. Visual and statistical analysis proved the efficiency of the proposed method as it significantly improved the fusion quality in comparison to conventional IHS technique. The accuracy of the proposed pan sharpening technique was also evaluated in terms of different spatial and spectral metrics. In this study, 7 metrics (Correlation Coefficient, ERGAS, RASE, RMSE, SAM, SID and Spatial Coefficient) have been used in order to determine the quality of the pan-sharpened images. Experiments were conducted on two different data sets obtained by two different imaging sensors, IKONOS and QuickBird. The result of this showed that the evaluation metrics are more promising for our fused image in comparison to other pan sharpening methods.

scholarly journals Analisis Komparasi Metode Pemetaan Ekosistem Mangrove Menggunakan Penginderaan Jauh dan Sistem Informasi Geografis

2020 ◽  
Vol 17 (2) ◽  
pp. 49-55
Author(s):  
Isma Yulia Rahma
Keyword(s):  
Forest Canopy ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Principal Component ◽  
Mangrove Ecosystem ◽  
Forest Canopy Density ◽  
Distribution Mapping ◽  
Information System Technology ◽  
The Right

The use of tools and methods in mapping mangrove ecosystem continues to change.Nowday's trend in mapping is to use remote sensing and digital geographic Information system technology. There are several commonly used methods for mapping the mangrove ecosystem, but we should be aware that choosing the right method of analysis will greatly support the quality of research. The research method is literature review from various books and accredited scientific journals. Subsequently conducted analysis of application methods of mapping mangrove ecosystem of various case studies and research needs. Based on research, there are five methods and analysis used i.e.manual interpretation with Mirror stereoscope, NDVI (Normalized Difference Vegetation Index) as the most common analysis for mangrove distribution mapping. Multivariat PCA (Principal Component Analysis), FCD (Forest Canopy Density) model, and copmpare methods to mapping the extensive changes of mangrove ecosystems. Therefore, this article can be an input for the prospective mangrove ecosystem researchers in determining the preciese method of analysis.  

scholarly journals SENSORIAMENTO REMOTO APLICADO AO MONITORAMENTO DE MACRÓFITAS AQUÁTICAS NO RESERVATÓRIO DE BARRA BONITA, SP

Irriga ◽  
2017 ◽  
Vol 22 (2) ◽  
pp. 330-342
Author(s):  
Renata Teixeira de Almeida Minhoni ◽  
Mírian Paula Medeiros André Pinheiro ◽  
Roberto Filgueiras ◽  
Celia Regina Lopes Zimback
Keyword(s):  
Supervised Classification ◽  
Aquatic Macrophytes ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Atmospheric Correction ◽  
Landsat 8 ◽  
Radiometric Calibration ◽  
Landsat 8 Oli ◽  
Boundary Definition ◽  
E Mail

SENSORIAMENTO REMOTO APLICADO AO MONITORAMENTO DE MACRÓFITAS AQUÁTICAS NO RESERVATÓRIO DE BARRA BONITA, SP  RENATA TEIXEIRA DE ALMEIDA MINHONI1; MÍRIAN PAULA MEDEIROS ANDRÉ PINHEIRO2; ROBERTO FILGUEIRAS3 E CÉLIA REGINA LOPES ZIMBACK4 1 Eng. Ambiental, Doutoranda em Agronomia (Irrigação e Drenagem) – FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu – SP, e-mail: [email protected] Eng. Agrônoma, Doutoranda em Agronomia (Irrigação e Drenagem) – FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu – SP, e-mail: [email protected] Eng. Agrícola e Ambiental, Doutorando em Engenharia Agrícola – UFV. Avenida Peter Henry Rolfs, s/n - Campus Universitário, CEP 36570-900, Viçosa - MG, e-mail: [email protected] Eng. Agrônoma, Professora. Doutora do Departamento de Solos e Recursos Ambientais - FCA/UNESP. Rua José Barbosa de Barros, 1780, CEP 18610-307, Botucatu – SP, e-mail: [email protected]  1 RESUMO Macrófitas aquáticas são organismos fotossintéticos, com tamanho suficiente para serem vistos a olho nu, que crescem submersas, flutuando ou sobre a superfície da água. A ação antrópica no represamento de corpos hídricos tem ocasionado a eutrofização dos recursos hídricos, e dentre os desequilíbrios que esta ação gera no meio aquático está à elevada proliferação de macrófitas. Devido a esse fato, essa pesquisa foi desenvolvida com o objetivo de realizar uma estimativa da área ocupada por macrófitas aquáticas no reservatório da Usina Hidrelétrica de Barra Bonita (SP), nos anos de 2013, 2014 e 2015. O estudo foi realizado na estação seca (mês de agosto), por meio do uso do NDVI (Normalized Difference Vegetation Index) e classificação supervisionada MAXVER (Máxima Verossimilhança). Para obtenção dos mapas e gráficos, foram realizadas as seguintes ações: seleção das imagens do satélite LANDSAT-8/OLI, calibração radiométrica, correção atmosférica, reprojeção, definição do limite, recorte da área, NDVI e classificação supervisionada. Os mapas obtidos por meio da classificação supervisionada, auxiliada pelos mapas de NDVI, apontaram para um aumento de aproximadamente 50% na área ocupada por macrófitas aquáticas de 2013 a 2015. Palavras-chave: classificação supervisionada, eutrofização, índice NDVI, landsat-8.  MINHONI, R. T. A.; PINHEIRO, M. P. M. A.; FILGUEIRAS, R.; ZIMBACK, C. R. L.REMOTE SENSING APPLIED TO THE MONITORING OF AQUATIC MACROPHYTES AT BARRA BONITA RESERVOIR, SP  2 ABSTRACT Aquatic macrophytes are photosynthetic organisms, large enough to be seen with naked eye, which grow submerged, floating or on the surface of the water. The anthropic action in the damming of water bodies has caused eutrophication of water resources, and among the imbalances that this action generates in the aquatic environment is the high proliferation of macrophytes. Due to this fact, this research was developed with the aim of estimating the area occupied by aquatic macrophytes in the reservoir of Barra Bonita Hydroelectric Power Plant (SP), in the years of 2013, 2014 and 2015. The study was carried out in the dry season (August), through the use of NDVI (Normalized Difference Vegetation Index) and supervised classification MAXVER (Maximum Likelihood). To obtain the maps and graphs, the following actions were taken: selection of LANDSAT-8 / OLI satellite images, radiometric calibration, atmospheric correction, reprojection, boundary definition, NDVI and supervised classification. The maps obtained through supervised classification, aided by NDVI maps, pointed to an increase of approximately 50% in the area occupied by aquatic macrophytes from 2013 to 2015. Keywords: supervised classification, eutrophication, NDVI index, landsat-8.

scholarly journals Durability and concentration of organic colorant in the visual quality of Discovery TM bermudagrass

2020 ◽  
Vol 26 (4) ◽  
pp. 621-632
Author(s):  
Matheus Vinícios Leal do Nascimento ◽  
Patrick Luan Ferreira dos Santos ◽  
João Victor Costa ◽  
Juliana Trindade Martins ◽  
Roberto Lyra Villas Bôas ◽  
...  
Keyword(s):  
Water Conservation ◽  
Color Index ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Visual Quality ◽  
Operating Costs ◽  
Aesthetic Quality ◽  
Green Color ◽  
Warm Weather

Abstract The painting of sports turfs with colorants is a common practice, with the main objective to maintain grass appearance for maximum aesthetic quality. Colorants are used to provide green color to grasses during periods of stress and dormancy and are considered an alternative for warm weather grasses during the winter months. Recent increases in the use of colorants is due to water conservation efforts as well as lower operating costs compared to winter overseeding. The objective of this study was to evaluate durability and doses of organic colorant in terms of visual quality of DiscoveryTM bermudagrass. The experiment was installed in the field, subdivided into plots of DiscoveryTM bermudagrass treated with lawn-specific commercial, organic colorant as follows 0 ml L-1 (Control); 33 ml L-1; 50 ml L-1; 66.6 ml L-1 (manufacturer’s recommendation); 83 ml L-1; 100 ml L-1. At 10 day intervals the green color index, reflectance, normalized difference vegetation index (NDVI), and digital images were measured and assessed. The results indicate that, given the durability of the product, doses between 66.6 and 83.3 ml L-1 are recommended.

scholarly journals ANALYZING RCD30 OBLIQUE PERFORMANCE IN A PRODUCTION ENVIRONMENT

2016 ◽  
Vol XLI-B3 ◽  
pp. 99-105 ◽  
Author(s):  
M. E. Soler ◽  
W. Kornus ◽  
A. Magariños ◽  
M. Pla
Keyword(s):  
Vegetation Index ◽  
Imaging System ◽  
Control Point ◽  
Resolving Power ◽  
Radiometric Calibration ◽  
Production Environment ◽  
Area Of Interest ◽  
The Absolute ◽  
The Impact

In 2014 the Institut Cartogràfic i Geològic de Catalunya (ICGC) decided to incorporate digital oblique imagery in its portfolio in response to the growing demand for this product. The reason can be attributed to its useful applications in a wide variety of fields and, most recently, to an increasing interest in 3d modeling. The selection phase for a digital oblique camera led to the purchase of the Leica RCD30 Oblique system, an 80MPixel multispectral medium-format camera which consists of one Nadir camera and four oblique viewing cameras acquiring images at an off-Nadir angle of 35º. The system also has a multi-directional motion compensation on-board system to deliver the highest image quality. <br><br> The emergence of airborne oblique cameras has run in parallel to the inclusion of computer vision algorithms into the traditional photogrammetric workflows. Such algorithms rely on having multiple views of the same area of interest and take advantage of the image redundancy for automatic feature extraction. The multiview capability is highly fostered by the use of oblique systems which capture simultaneously different points of view for each camera shot. Different companies and NMAs have started pilot projects to assess the capabilities of the 3D mesh that can be obtained using correlation techniques. Beyond a software prototyping phase, and taking into account the currently immature state of several components of the oblique imagery workflow, the ICGC has focused on deploying a real production environment with special interest on matching the performance and quality of the existing production lines based on classical Nadir images. <br><br> This paper introduces different test scenarios and layouts to analyze the impact of different variables on the geometric and radiometric performance. Different variables such as flight altitude, side and forward overlap and ground control point measurements and location have been considered for the evaluation of aerial triangulation and stereo plotting. Furthermore, two different flight configurations have been designed to measure the quality of the absolute radiometric calibration and the resolving power of the system. <br><br> To quantify the effective resolution power of RCD30 Oblique images, a tool based on the computation of the Line Spread Function has been developed. The tool processes a region of interest that contains a single contour in order to extract a numerical measure of edge smoothness for a same flight session. The ICGC is highly devoted to derive information from satellite and airborne multispectral remote sensing imagery. A seamless Normalized Difference Vegetation Index (NDVI) retrieved from Digital Metric Camera (DMC) reflectance imagery is one of the products of ICGC’s portfolio. As an evolution of this well-defined product, this paper presents an evaluation of the absolute radiometric calibration of the RCD30 Oblique sensor. To assess the quality of the measure, the ICGC has developed a procedure based on simultaneous acquisition of RCD30 Oblique imagery and radiometric calibrated AISA (Airborne Hyperspectral Imaging System) imagery.

scholarly journals The Utilization of Supervised Classification Sampling for Environmental Monitoring in Turin (Italy)

2021 ◽  
Vol 13 (5) ◽  
pp. 2494
Author(s):  
Stefano Salata
Keyword(s):  
Land Use ◽  
Environmental Monitoring ◽  
Supervised Classification ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Just In Time ◽  
Environmental Status ◽  
Wide Range ◽  
The City

In a world threatened by climate change, the need to observe the land transformation is crucial to set environmental policies. One of the most prominent issues of environmental monitoring is the availability of updated and reliable land use data. The last land-use release in Piedmont Region (Italy) is in 2010, while the most updated Normalized Difference Vegetation Index is in 2016. To overcome this limit, in this study, a supervised classification sampling has been applied on a Sentinel-2 image produced by the Copernicus Program on 29 September 2020, using Esri ArcGIS (ver.10.8 Redlands, California, US) by accessing via ONDA-DIAS services to L2A products. After land classification, three maps were generated—the Habitat Quality, the Habitat Decay, and the Normalized Difference Vegetation Index. This study aimed at classifying the environmental status in five classes ranging from “critical” to “health” with a double perspective—(i) to make a comparative metropolitan assessment between municipalities and (ii) to evaluate the quality of urban public green areas in the city of Turin while defining a different kind of intervention. Results indicate that products derived from supervised classification sampling can be applied in a wide range of applications while reaching seasonal monitoring of the environmental status and delivering just-in-time solutions.

CryoSat Mission and data products status after 10 years of operation

2020 ◽  
Author(s):  
Marco Meloni ◽  
Jerome Bouffard ◽  
Tommaso Parrinello ◽  
Erica Webb ◽  
Ben Wright ◽  
...  
Keyword(s):  
Earth Science ◽  
Ice Sheets ◽  
Quality Of Data ◽  
Extended Phase ◽  
Data Products ◽  
Global Sea Level ◽  
New Research ◽  
The Antarctic ◽  
Scientific Questions

<p>The ESA Earth Explorer CryoSat-2 was launched on 8 April 2010 and from an altitude of just over 700 km and reaching latitudes of 88 degrees, monitors precise changes in the thickness of terrestrial ice sheets and marine ice. The aim of the CryoSat-2 mission is to determine variations in the thickness of the Earth's marine ice cover and understand the extent to which the Antarctic and Greenland ice sheets are contributing global sea level rise. In its 10 years of operations, CryoSat has achieved its mission objectives and has provided high-quality of data for a number of Earth science applications and opened up new research streams and triggered new scientific questions which have emerged from the previous phases. The purpose of this paper is to provide a general overview of the mission status and provide programmatic highlights in its new extended phase until 2021. It will also provide an overview of CryoSat data products covering both Ocean and Ice processing chains, presenting also the main evolutions and improvements that have implemented to the processors and anticipating evolutions for the future. </p><p> </p>

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