scholarly journals Error Analysis of Atmospheric Visibility Measurements Based on an Image Brightness Contrast Method

IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 48408-48415
Author(s):  
Min Wang ◽  
Shu-Dao Zhou ◽  
Zhong Yang ◽  
Zhan-Hua Liu
2013 ◽  
Vol 321-324 ◽  
pp. 656-662 ◽  
Author(s):  
Qian Qian Liu ◽  
Bin Zhang

Based on digital camera method, there was using an improved dual-target method to measure atmospheric visibility. Using a digital camera to obtain images selected targets under different weather, to brightness contrast method and dual-target method were used to edge detection and Hough transform to obtain the image of the target and background, then respectively through the brightness contrast method and dual target method to calculate visibility value, in view of the different weather will dual target method and brightness contrast method and meteorological bureau issued the visibility value contrast experiment. Comparison results show that the digital camera method for visibility value and weather bureau data released by the trend is almost the same, especially dual target method. Digital camera method proved the effectiveness of Qingdao area visibility observation.


1978 ◽  
Vol 22 (1) ◽  
pp. 227-229 ◽  
Author(s):  
William F. Moroney ◽  
James F. Barnette

The human factors considerations in the design and evaluation of a helmet mounted display (HMD) using a light emitting diode (LED) matrix are discussed. Specific issues including: helmet weight, bulk, image brightness/contrast, exit pupil size, reduction in visual field, and restriction of head movement were addressed and tradeoffs evaluated. The HMD was evaluated in flight as a device to provide energy maneuverability data to pilots. Preliminary findings are discussed.


2020 ◽  
Vol 37 (12) ◽  
pp. 2299-2305
Author(s):  
Min Wang ◽  
Shudao Zhou ◽  
Zhanhua Liu ◽  
Yangchun Zhang

AbstractThe reflection of colors and surfaces of common targets lead to errors in the measurement of visibility by the image method. This study aims to investigate the problem of inaccurate visibility detection. Through analysis of the error of visibility measurement caused by the reflection of the blackboard surface of an artificial target, the design method of improving the structure of the target board is proposed, so as to improve the accuracy of atmospheric visibility measurement by the image method. The experimental results show that the new target board designed by this method can greatly improve the measurement accuracy of the intrinsic apparent brightness ratio, which can increase 18.4% in the fairing environment and closer to −1 in the side light environment. Therefore, when the side light is selected for the image method visibility measurement, more accurate visibility results can be obtained.


2021 ◽  
Vol 1 (1) ◽  
pp. 6-12
Author(s):  
Fitri Rizani

The ability of computers that are increasingly reliable in various fields, especially in helping the image processing sector through improving image quality, is very much felt so that the empowerment of computers at any time needs to be improved. Image quality improvement can be made with various techniques, including Image Quality Improvement with Image Brightness and Image Sharpening methods. The process begins with capturing the image and then continues with increasing the intensity of brightness, image contrast and sharpening. Image processing results are indicated by changes in the resulting image and changes in the image histogram


1999 ◽  
Vol 173 ◽  
pp. 185-188
Author(s):  
Gy. Szabó ◽  
K. Sárneczky ◽  
L.L. Kiss

AbstractA widely used tool in studying quasi-monoperiodic processes is the O–C diagram. This paper deals with the application of this diagram in minor planet studies. The main difference between our approach and the classical O–C diagram is that we transform the epoch (=time) dependence into the geocentric longitude domain. We outline a rotation modelling using this modified O–C and illustrate the abilities with detailed error analysis. The primary assumption, that the monotonity and the shape of this diagram is (almost) independent of the geometry of the asteroids is discussed and tested. The monotonity enables an unambiguous distinction between the prograde and retrograde rotation, thus the four-fold (or in some cases the two-fold) ambiguities can be avoided. This turned out to be the main advantage of the O–C examination. As an extension to the theoretical work, we present some preliminary results on 1727 Mette based on new CCD observations.


Author(s):  
N.S. Allen ◽  
R.D. Allen

Various methods of video-enhanced microscopy combine TV cameras with light microscopes creating images with improved resolution, contrast and visibility of fine detail, which can be recorded rapidly and relatively inexpensively. The AVEC (Allen Video-enhanced Contrast) method avoids polarizing rectifiers, since the microscope is operated at retardations of λ/9- λ/4, where no anomaly is seen in the Airy diffraction pattern. The iris diaphram is opened fully to match the numerical aperture of the condenser to that of the objective. Under these conditions, no image can be realized either by eye or photographically. Yet the image becomes visible using the Hamamatsu C-1000-01 binary camera, if the camera control unit is equipped with variable gain control and an offset knob (which sets a clamp voltage of a D.C. restoration circuit). The theoretical basis for these improvements has been described.


Author(s):  
O. T. Inal ◽  
L. E. Murr

When sharp metal filaments of W, Fe, Nb or Ta are observed in the field-ion microscope (FIM), their appearance is differentiated primarily by variations in regional brightness. This regional brightness, particularly prominent at liquid nitrogen temperature has been attributed in the main to chemical specificity which manifests itself in a paricular array of surface-atom electron-orbital configurations.Recently, anomalous image brightness and streaks in both fcc and bee materials observed in the FIM have been shown to be the result of surface asperities and related topographic features which arise by the unsystematic etching of the emission-tip end forms.


Author(s):  
D.F. Bowling

High school cosmetology students study the methods and effects of various human hair treatments, including permanents, straightening, conditioning, coloring and cutting. Although they are provided with textbook examples of overtreatment and numerous hair disorders and diseases, a view of an individual hair at the high resolution offered by an SEM provides convincing evidence of the hair‘s altered structure. Magnifications up to 2000X provide dramatic differences in perspective. A good quality classroom optical microscope can be very informative at lower resolutions.Students in a cosmetology class are initially split into two groups. One group is taught basic controls on the SEM (focus, magnification, brightness, contrast, specimen X, Y, and Z axis movements). A healthy, untreated piece of hair is initially examined on the SEM The second group cements a piece of their own hair on a stub. The samples are dryed quickly using heat or vacuum while the groups trade places and activities.


1995 ◽  
Vol 11 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Dietmar Heubrock

Performance on a German version of the Rey Auditory-Verbal Learning Test (AVLT) was investigated for 64 juvenile patients who were subdivided in 6 clinical groups. In addition to standard evaluation of AVLT protocols which is usually confined to items recalled correctly, an error analysis was performed. Differentiating between total errors (TE), repetition errors (RE), and misnamings (ME), substantial differences between clinical groups could be demonstrated. It is argued that error analysis of verbal memory and learning enriches the understanding of neuropsychological syndromes, and provides additional information for diagnostic and clinical use. Thus, it is possible to gain a more accurate picture so that patients can be appropriately retrained, and research into the functional causes of memory and learning disorders can be intensified.


1994 ◽  
Vol 4 (10) ◽  
pp. 1999-2012 ◽  
Author(s):  
Nabil Derbel ◽  
Mohamed B.A. Kamoun ◽  
Michel Poloujadoff

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