Optical Telescope TechnologyScientific and Technical Information Division, National Aeronautics and Space Administration, 1970 - 783 էջ Design optics and technology for large spaceborne astronomical telescopes. |
From inside the book
Արդյունքներ 100–ի 1-ից 5-ը:
Էջ 14
... signal- to - noise ratio of about 25 for a 1 - minute exposure with a contribution from the sky background of the same order as the object . An 80 - inch - diameter telescope with a 1 - second - of - arc diaphragm could carry out ...
... signal- to - noise ratio of about 25 for a 1 - minute exposure with a contribution from the sky background of the same order as the object . An 80 - inch - diameter telescope with a 1 - second - of - arc diaphragm could carry out ...
Էջ 76
... signal is not derived by operation on the signals from the experiment telescope . The unit is designed to perform offset pointing by changing the orientation of the fine - pointing telescope with respect to the experiment telescope ...
... signal is not derived by operation on the signals from the experiment telescope . The unit is designed to perform offset pointing by changing the orientation of the fine - pointing telescope with respect to the experiment telescope ...
Էջ 79
... signal path that would not be there with the nominally nulled system . The impression is that this method would be satisfactory for small systems but would introduce too much image distortion into the larger systems . Servoed Platform ...
... signal path that would not be there with the nominally nulled system . The impression is that this method would be satisfactory for small systems but would introduce too much image distortion into the larger systems . Servoed Platform ...
Էջ 86
... signal - to - noise ratio by which each one of n spectral components of a spectrum is known . The advantage arises . because , multiplexing , we look with a detector at all spectral components con- currently for a longer time , nт ...
... signal - to - noise ratio by which each one of n spectral components of a spectrum is known . The advantage arises . because , multiplexing , we look with a detector at all spectral components con- currently for a longer time , nт ...
Էջ 89
... signal from the scene imaged on its front photo- sensor surface . The mechanism of scanning permits charge storage , thereby enhancing signal - to - noise capability but operating with a 89 PHOTOELECTRONIC IMAGING DEVICES SOL NUDELMAN.
... signal from the scene imaged on its front photo- sensor surface . The mechanism of scanning permits charge storage , thereby enhancing signal - to - noise capability but operating with a 89 PHOTOELECTRONIC IMAGING DEVICES SOL NUDELMAN.
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Common terms and phrases
alignment analysis angstroms applied arc second array astronomical axis beam beryllium calibration Cer-Vit chamber collimator command configuration curve dark current detector developed diameter dynamic electron elements energy environment equipment experiment package facility film filter flux frequency function gimbal heat pipes inches infrared input instrument irradiance Kitt Peak layer lens light load material measurements ment microns mission mode module mounted nanoamperes Observatory obtained operation optical orbit Orbiting Astronomical Observatory p-n junction percent performance photocathode plate Plumbicon primary mirror problem protons pumps radiation ratio reflectance resolution scanning SEC camera tube SEC target secondary mirror sensor shown in figure signal simulation solar space telescope spacecraft spectral stability star trackers stresses structure surface tape techniques temperature thermal thickness tion torque transmission ultraviolet vacuum vehicle vibration vidicon voltage wavelength
Սիրված հատվածներ
Էջ 261 - Evaluation of Multipoint Interaction in the Design of a Thin Diffraction-Limited Active Mirror.
Էջ 589 - ... A low energy electron beam scans the surface of the silicon depositing charge such that the p-regions exposed to the beam are brought to cathode potential. Thus pn junctions are reverse biased by the beam. During the time that the electron beam is not on an element, the reverse bias voltage across the pn junction decreases as the result of transfer of charge across the junction. This charge arises from either internal generation of free carriers in the material or by photoexcited carriers in...
Էջ 187 - It is the purpose of this discussion to point out some of the possibilities of teaching shop processes in this manner. As Mr. Hesse indicated, "Shop Processes" is an extensive subject and its teaching must be regarded as a continuous project.
Էջ viii - Application of finite element techniques to the design and manufacture of astronomical mirrors...
Էջ 621 - Laboratory for Astrophysics and Space Research of the Enrico Fermi Institute for Nuclear Studies at the University of Chicago — one of the first such university centers in the country. Here, in the sub-basement, in a concrete-shielded counting laboratory, scientists measure radioactivity of meteorites and "space dust" scraped from space flight capsules.
Էջ 296 - Cowper, GR: The Shear Coefficient in Timoshenko's Beam Theory.
Էջ 326 - March 1967. 9. Koopmans, TC, ed.: Activity Analysis of Production and Allocation. Cowles Commission, University of Chicago, 1951.
Էջ 241 - It is convenient in computation to use the same numbering system for bars, torsion bars, and joints. So far in these developments bars have been referred to as a and b. Referring to the numbering system shown above, it will be recognized that in reality a becomes i and b becomes i+1.
Էջ 392 - The two 150-inch telescopes for the Kitt Peak National Observatory and the Cerro Tololo Inter-American Observatory in Chile have solid mirrors of fused silica and Cer-Vit, respectively.
Էջ 679 - ... high cost for large aperture systems. Digital processing has the advantages of being extremely flexible, rather trouble-free and easy to use, once the programming system has been worked out. It also has the ability to handle problems which are nonlinear in both intensity and geometry and can solve these with an accuracy limited only by the user's knowledge of the incoming data. To...