Sharpness indicator of aerial- and space images obtained for mapping purposes

2020 ◽  
Vol 960 (6) ◽  
pp. 35-44
Author(s):  
I.A. Anikeeva
Keyword(s):  
Spatial Resolution ◽  
Aerial Survey ◽  
Local Contrast ◽  
Profile Curve ◽  
Image Sharpness ◽  
Space Images ◽  
Space Imagery ◽  
Accuracy Of Measurements ◽  
Edge Profile ◽  
Visual Properties

The main characteristics of aerial- and space imagery, obtained for mapping purposes, are the distinct details transferring and sharpness, which determine their visual properties. The sharpness of aerial- and space images affects the accuracy of measurements made on them, as well as the quality products obtained. The ability of the image to transfer fine details is separately determined by its actual spatial resolution. It is shown that the actual resolution does not completely represent the structural-and-geometric characteristics of the images’ fine quality. Calculations showing that neither actual spatial resolution nor the gradation characteristic “local contrast” make it possible to evaluate its sharpness are presented. The author proposes a method of numerically image sharpness assessing, based on the gradient characteristic of the edge profile curve. The advantage of this method in comparison with alternative ones is shown. The general form of the image sharpness criteria calculating formula for any radiometric resolution is given. The proposed method enables obtaining a normed value, varying from 0 to 1, which provides obvious interpretability of the result. The permissible value of the sharpness index of aerial and space imagery obtained for mapping is determined. Examples of images obtained by an aerial survey complex based on a light drone, as well as those obtained by a remote sensing spacecraft, satisfying the established acceptable sharpness criteria, are given. The correspondence of obtained numerical estimates to the visual perception of the image sharpness is shown.

Comparative analysis of satellite images obtained by spacecraft “Canopus-V” and “Aist-2D”

2019 ◽  
Vol 949 (7) ◽  
pp. 39-50
Author(s):  
I.A. Anikeeva ◽  
N.Yu. Litvinov ◽  
S.S. Nekhin
Keyword(s):  
Comparative Analysis ◽  
Remote Sensing Data ◽  
Sampling Interval ◽  
Local Contrast ◽  
Advantages And Disadvantages ◽  
Space Imagery ◽  
Transfer Characteristics ◽  
Accuracy Of Measurements ◽  
Mapping Scale ◽  
Transfer Properties

A comparative analysis of the remote sensing data, obtained by spacecrafts “Canopus-V” and “Aist-2D”, in terms of determining their actual spatial resolution – the smallest linear size of the terrain object that can be transmitted by the image. Within the researches of studied space imagery structural transfer properties the calculations of their general and local contrast for different types of underlying surface were performed. In particular, it was shown, that despite the smaller ground sampling interval (GSI), images, obtained by “Aist-2D”, are comparable in their structural transfer characteristics to the images of “Canopus-V” because of the greater blurring. However, “Canopus-V” images have a disadvantage – the artifacts due to direct solar reflection from smooth (mirror) surfaces, which “Aist-2D” images do not have. Basing on the obtained values of structural transfer characteristics and the requirements of the Instructions on photogrammetric work for digital topographic maps and plans creation, the mapping scale, corresponding the attainable accuracy of measurements, made by images, obtained by spacecrafts “Canopus-V” and “Aist-2D”, is determined. The conclusions about the comparability of considered space imagery structural transfer characteristics, the advantages and disadvantages in terms of their photographic quality, as well as the possibility of their use for mapping purposes are formulated.

Image Sharpness and Contrast Tuning in the Early Visual Pathway

2017 ◽  
Vol 27 (08) ◽  
pp. 1750045 ◽  
Author(s):  
Eduardo Sánchez ◽  
Rubén Ferreiroa ◽  
Adrián Arias ◽  
Luis M. Martínez
Keyword(s):  
Functional Organization ◽  
Ganglion Cells ◽  
Receptive Fields ◽  
Local Contrast ◽  
Retinal Ganglion ◽  
Image Sharpness ◽  
Image Processing Techniques ◽  
Thalamic Relay ◽  
Processing Techniques

The center–surround organization of the receptive fields (RFs) of retinal ganglion cells highlights the presence of local contrast in visual stimuli. As RF of thalamic relay cells follow the same basic functional organization, it is often assumed that they contribute very little to alter the retinal output. However, in many species, thalamic relay cells largely outnumber their retinal inputs, which diverge to contact simultaneously several units at thalamic level. This gain in cell population as well as retinothalamic convergence opens the door to question how information about contrast is transformed at the thalamic stage. Here, we address this question using a realistic dynamic model of the retinothalamic circuit. Our results show that different components of the thalamic RF might implement filters that are analogous to two types of well-known image processing techniques to preserve the quality of a higher resolution version of the image on its way to the primary visual cortex.

Monitoring the state of waste disposal facilities using remote sensing data

2018 ◽  
Vol 941 (11) ◽  
pp. 47-53
Author(s):  
U.D. Niyazgulov ◽  
A.A. Gebgart ◽  
V.G. Krestinkov ◽  
F.K. Niyazgulov
Keyword(s):  
Remote Sensing ◽  
Spatial Resolution ◽  
Imaging System ◽  
Remote Sensing Data ◽  
Aerial Survey ◽  
The State ◽  
Household Waste ◽  
Ecological State ◽  
Solid Waste Landfills ◽  
The Impact

The technology of monitoring objects of solid household waste in the Moscow region using the data of space and aerial survey is considered. In order to solve the problem, we used space survey materials obtained from the Worldview-2 satellite (spatial resolution of 1,5 m per pixel) and special aerial filming performed with the help of an Azimuth-2M photo-imaging system based on a hang glider (spatial resolution not coarser than 0,1 m per pixel). On the basis of those materials, digital models of accommodation facilities for solid household wastes and orthophotoplans were obtained, using which a comparative analysis of the state of landfills was performed. The analysis was carried out according to several indicators, including the impact of polygons on the ecological state of the surrounding territories and the cluttering the surrounding territory with waste was determined. It is shown that the use of remote sensing materials enables obtaining the necessary information to monitor the state of solid waste landfills, while performing the minimum amount of field geodetic works.

scholarly journals Selection of informative features to highlight areas of waste disposal on high spatial resolution satellite imagery

2019 ◽  
pp. 29-44
Author(s):  
A. B. Murynin ◽  
A. A. Richter ◽  
M. A. Shakhramanyan
Keyword(s):  
Spatial Resolution ◽  
Satellite Imagery ◽  
Waste Disposal ◽  
High Spatial Resolution ◽  
Ground Truth ◽  
Space Images ◽  
Radar Images ◽  
High Resolution Images ◽  
Interpretive Signs ◽  
Selection Of

The paper deals with the problem of integrated interpretation of waste disposal facilities according to satellite imagery and ground truth monitoring, features of space images of landfills from various points of view: texture analysis, statistical properties, fractal analysis, color features, and the possibility of using machine learning methods. The main visual interpretive signs of landfills on optical and radar images of high spatial resolution are given. The fractal dimension of landfills was calculated for high resolution images using two models.

Predicting topsoil organic carbon using UAV-based hyperspectral sensor

2020 ◽  
Author(s):  
János Mészáros ◽  
Gergely Jakab ◽  
Mátyás Árvai ◽  
Judit Szabó ◽  
Márton Tóth ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Spatial Resolution ◽  
Land Surface ◽  
Spatial Information ◽  
Principal Component ◽  
Spatial Prediction ◽  
Aerial Survey ◽  
Electromagnetic Spectrum ◽  
Spectral Bands ◽  
Significant Difference

<p>There is increasing demand for up‐to‐date spatial information on soil organic carbon (SOC). Meanwhile, Unmanned Aerial Vehicles (UAV) provide flexible technology for monitoring land surface features with high spatial resolution at plot scale. Suitably performed, airborne imagery simultaneously provides spectral and terrain based spatial auxiliary data, which can be used as predictors in DSM-type modelling of topsoil OC.</p><p>To test its applicability for spatial prediction of topsoil OC, an aerial survey was carried out on a plot situated on a gently undulating slope by a Cubert UHD-185 hyperspectral snapshot camera mounted on a Pixhawk-based octocopter. The camera is capable to record electromagnetic spectrum between 450-950 nm in 125 spectral bands on 50×50 pixels images and the panchromatic spectrum in 1 Mpx images. Because of the narrow field-of-view of the UHD-185, three consecutive flights were needed to cover the whole area (cca. 10 ha); all were happened in the hours close to noon and flown in automatic flight mode to ensure the right over- and sidelap between images to make possible the photogrammetric processing. Despite the automatic flights a surveying grade GPS unit was also used to survey 12 markers, evenly distributed on the field to orthorectify images later.</p><p>The hyperspectral and panchromatic images were pre-processed in Cubert Edelweiss to produce different versions of them depending on the used spectral information to investigate later how built-in pan-sharpening method affects the prediction accuracy. The generated datasets are the native and pan-sharpened hyperspectral mosaics. Later the photogrammetric processing was performed in Agisoft Photoscan for both hyperspectral datasets, resulting in two georeferenced outcomes: a common digital elevation model (DEM) and two hyperspectral orthomosaics of the area, each exported with 1 m spatial resolution. Further data editing steps were carried out in R, generating various versions of exported hyperspectral orthomosaics: mosaic containing all of the 125 spectral bands; filtered (where spectrally overlapping bands with high correlation were removed based on Full Width at Half Minimum information) and Principal Component Analysis transformed versions.</p><p>Based on different kind of spectral orthomosaics and DEM combinations, a custom R script using Random Forest algorithm generated 36 predicted layers for topsoil OC, which were validated by Leave-One-Out Cross-Validation, hence independent mean and RMSE errors could be calculated for each dataset combinations. The overall best performing datasets were provided by the FWHM-filtered hyperspectral orthomosaic, hence the lowest mean error is resulted by the filtered, pan-sharpened PCA-transformed combination containing the DEM and its derivatives. However, in the RMSE values there were no significant difference between the six lowest RMSE combinations, but mostly the pan-sharpened and PCA-transformed versions perform better.</p>

scholarly journals ANALYSIS OF UAV IMAGE QUALITY USING EDGE ANALYSIS

2018 ◽  
Vol XLII-4 ◽  
pp. 359-364
Author(s):  
P.-C. Lim ◽  
T. Kim ◽  
S.-I. Na ◽  
K.-D. Lee ◽  
H.-Y. Ahn ◽  
...  
Keyword(s):  
Image Quality ◽  
Spatial Resolution ◽  
Rating Scales ◽  
Signal To Noise Ratio ◽  
Weather Conditions ◽  
Resolving Power ◽  
Modulation Transfer ◽  
Image Sharpness ◽  
Actual Performance ◽  
Uav Images

<p><strong>Abstract.</strong> UAVs (Unmanned aerial Vehicles) can acquire images easily without large cost. For this reason, use of UAV is spreading to diverse fields such as orthoimages and DEM/DSM production. The spatial resolution of images is usually expressed as a GSD (Ground Sampling Distance). The GSD from UAV has higher performance than other platforms such as satellites and aircraft because it shoot at low altitude. However, blurring and noise may occur on UAV images due to the weather and the stability of UAV. However, since the GSD from UAV cannot sufficiently meet the spatial resolving power of the actual image system, a criterion for determining the spatial resolution of image is needed. Therefore we emphasize that the quality of the image needs to be analysed. Actual performance indicators such as GRD (Ground Resolved Distance) and NIIRS (National Image Interpretability Rating Scales), which can be measured through image analysis, are representative examples of image quality interpretation. It is possible to extract NIIRS form image quality related parameters such as MTF (Modulation Transfer Function), RER (Relative Edge Response) and SNR (Signal to Noise Ratio). In this paper, we aim to apply the Edge analysis method to UAV and to analyse the result. The analysis result showed that while GSD and NIIRS were highly dependent to imaging altitude, GRD and image sharpness showed optimal altitude ranges. The exact optimal range varied between images taken at different weather conditions. While we need a further study, this may indicate that edge analysis may provide an optimal operational altitude range suitable for the sensors.</p>

A study of small probe formation in a field emission gun TEM/STEM

1988 ◽  
Vol 46 ◽  
pp. 510-511
Author(s):  
J. K. Veiss ◽  
R. W. Carpenter
Keyword(s):  
Field Emission ◽  
Spatial Resolution ◽  
Current Distribution ◽  
Electron Microprobe ◽  
Real Space ◽  
High Magnification ◽  
Resolution Method ◽  
Space Images ◽  
High Brightness ◽  
Small Probe

A Philips EM 400T equipped with a field emission gun (FEG) has been studied to determine the spatial and angular current distribution in the electron microprobe at the specimen level. The field emission gun provides a high brightness source capable of producing electron probes with diameters of several nanometers and total currents of 0.05 - 50 nA. The advantage of the TEM/STEM over the dedicated STEM in this study is its ability to produce real-space images of the probe at the specimen plane. Detailed information about the probe current distribution can be experimentally obtained and applied to various small-probe techniques (i.e. HRAEM, STEM, microdiffraction) in order to determine their spatial resolution.The probe diameters listed in Table 1 were measured from high magnification images of the focussed probes which showed sharply defined outlines of the aberration figures. Additional measurements were obtained by scanning the probe across a small fixed entrance aperture to an EELS spectrometer, and also by an edge resolution method similar to that used by Venables and Janssen.

scholarly journals LAND USE AND LAND COVER MAPPING IN DETAILED SCALE: A CASE STUDY IN SANTA ROSA DE LIMA-SC

2018 ◽  
Vol 24 (2) ◽  
pp. 217-234 ◽  
Author(s):  
Rodrigo de Campos Macedo ◽  
Abdon Luiz Schmitt Schmitt Filho ◽  
Joshua C. Farley ◽  
Alfredo Celso Fantini ◽  
Ademir Antonio Cazella ◽  
...  
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Spatial Resolution ◽  
Temporal Resolution ◽  
Large Scale ◽  
Aerial Survey ◽  
Aerial Photographs ◽  
High Temporal Resolution ◽  
Land Cover Mapping

Abstract: It is challenging to reconcile large scale data with the dynamic characteristics present in land use. Such dynamism requires data with a high repetition of sampling. An alternative is the integration of data of high spatial resolution and low temporal resolution, with that of high temporal resolution and low spatial resolution. The aim addressed in this article is related to the integration of aerial photographs and temporal series for land use and land cover mapping in high detail scale. We conducted a case study in Santa Rosa de Lima-SC. The main data used was the aerial survey that overlaid the state of Santa Catarina, executed in 2010/2011. The interpretation key included typical elements of photointerpretation (color, texture, size, shape), aiming to classify the land use and land cover classes. The mapping evaluation resulted in 75.6% global accuracy, ranging from 54% (Grassland and Wetlands) to 96% (Water Bodies and Rocks). Such results are considered satisfactory. The integration of high-resolution images with high temporal resolution data has enabled the discrimination between classes that present great difficulties of separability. Such discrimination is essential in the territorial management processes of Encosta da Serra and the municipality of Santa Rosa de Lima.

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