LOCATION AND DETERMINATION OF THE LOCATION OF THE ENTRANCE PUPIL (CENTER OF PROJECTION) OF PC-1000 CAMERA IN OBJECT SPACE

1962 ◽  
Author(s):  
Duane C. Brown ◽  
Ronald G. Davis
Keyword(s):  
Entrance Pupil ◽  
Object Space ◽  
Pupil Center

scholarly journals USING SMART PHONES FOR DEFORMATIONS MEASUREMENTS OF STRUCTURES

2017 ◽  
Vol 43 (2) ◽  
pp. 66-72 ◽  
Author(s):  
Khalid L. A. EL-ASHMAWY
Keyword(s):  
Least Squares ◽  
Smart Phones ◽  
Digital Cameras ◽  
Object Space ◽  
Close Range Photogrammetry ◽  
Variable Displacement ◽  
Close Range ◽  
Displacement Transducers ◽  
Better Than

The present work tests the suitability of using the digital cameras of smart phones for close range photogrammetry applications. For this purpose two cameras of smart phones Lumia 535 and Lumia 950 XL were used. The resolutions of the two cameras are 5 and 20 Mpixels respectively. The tests consist of (a) self calibration of the two cameras, (b) the implementation of close-range photogrammetry using the cameras of the two smart phones, theodolite intersection with LST method, and linear variable displacement transducers (LVDTs) for the measurement of vertical deflections, and (c) accuracy of photogrammetric determination of object space coordinates. The results of using Lumia 950 XL are much better than using Lumia 535 and are better or comparable to the results of theodolite intersection with least squares technique (LST). Finally, it can be stated that the digital cameras of smart phones are suitable for close range photogrammetry applications according to accuracy, costs and flexibility.

scholarly journals Experimentelle Bestimmung der öffnungsfehlerkonstante von Elektronenkanonen / Experimental Determination of the Spherical Aberration Constant of Electron Guns

1973 ◽  
Vol 28 (12) ◽  
pp. 1937-1945 ◽  
Author(s):  
Rolf Lauer
Keyword(s):  
Experimental Determination ◽  
Spherical Aberration ◽  
Shadow Method ◽  
Entrance Pupil ◽  
Electron Guns ◽  
The Cross ◽  
Pass Through ◽  
Theoretical Considerations

Due to the spherical aberration of electron guns, rays with large inclinations will not pass through the cross-over (the image of the entrance pupil). In order to calculate the constant of spherical aberration, it is necessary to know the transverse aberration as a function of the ray inclination at the cathode. Because measurements near the cathode are not possible, the size of the entrance pupil has been determined by theoretical considerations. The additional knowledge of cross-over size and inclinations of the emerging rays is then sufficient for obtaining the ray data at the cathode. The cross-over has been determined indirectly, ray inclination and transverse aberration in the cross-over plane have been measured by means of a shadow method.

Phase measuring deflectometry based on calibrationof the entrance pupil center of the camera lens

2022 ◽  
Author(s):  
Renhao Ge ◽  
Dahai Li ◽  
Xinwei Zhang ◽  
Ruiyang Wang ◽  
Wanxing Zheng ◽  
...  
Keyword(s):  
Entrance Pupil ◽  
Camera Lens ◽  
Pupil Center

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

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