... These are the filter transmission, the field of view (determined by the NICMOS optics external to the dewar, in combination with the HST mirrors), the reflectivities of the various external mirrors and the transmission of the dewar window. ... The sensitivity will obviously be affected by the pixel field of view. ... Finally, the optical efficiency will be degraded further by the reflectivities of the aluminum with MgF 2 overcoated HST primary and secondary mirrors. ... Primary mirror temperature . ...

... Meade Series 4000 Nebular Filters incorporate the very latest in interference coatings technology. ... Technical Basis of the Meade Broadband Nebular Filter: As shown in the transmission graph below, the Meade Broadband Nebular Filter strongly rejects the light of sodium- and mercury-vapor lights as well as natural airglow and auroral emissions. ... Meade Series 4000 Narrowband Nebular Filters . ... Meade Series 4000 Oxygen-III Nebular Filters . ... Meade Series 4000 Photo-Visual Color Filters . ...

... Обзор LPR фильтра. Впечатления от наблюдений с LPR фильтром. ... Характеристики цветных фильтров Baader-Planetarium . Мой перевод pdf- файла о фильтрах с сайта Baader-Planetarium (379 кб) . ...

... This noise can be reduced by replacing the pixels with an average of the surrounding values using a linear filter. ... The effects of applying linear filters to a CCD frame is shown in Figure . Figure: Different digital filters applied on a CCD image: (A) original, (B) block filter, (C) smooth filter, and (D) Laplacian filter. ... To remove stellar images from a picture of comet Halley, the results of applying different non--linear filters to the frame are given in Figure . ...

Next: AXAF Recipes Up: ROSAT HRI Recipes Previous: Quantum Efficiency Correction (a.k.a. For some observations, a significant amount of data may have been rejected during SASS processing because the background level was higher than the calculated threshold for rejection. ... REJECTED EVENTS . ... The recipe will allow the user to include rejected events in the generation of a new qpoe file and filter on the background level. ... This creates a qpoe file with standard + rejected events. ...

Infrared Detector Array Links . ... Control Software Links . Optics Links . Micro-Optics Links . ... Optical Materials Databases . ... Atmospheric Database Links . Linux Links . ... Rockwell Science Center home page. ... Santa Barbara Research Center home page. ... CCD-World home page. ... SDSU home page. ... EPICS home page. ... Optics Society of America . ... Linux on Laptops ( local site and US home page ). ... Instrumentation Links * Gemini Project Links * Other IR Instruments ...

The overall efficiency (including atmospheric transmission, reflectivity of the telescope mirrors and overall efficiency of the optics and of the detector) for broad-band imaging should be about 25% in H and K, and about 15% in J. The main noise source for both broad- and narrow-band imaging should be the photon noise associated to the background+source flux. ... Flat fielding (and possibly background subtraction) might increase the noise by a factor 2 ? ...

... 03oct13:plot filter shapes and aliased power. dec=2..15 . 02may08: simulate lpdf, look at rms vs decimation. ... The mock spectrometer has a low pass digital filter after the a/d, digital mixer section. ... Plots were made of the filter shapes (in the time and frequency domain) for decimations 2 through 15 using the filter coefficients. ... The x axis scale is the unfiltered bandwidth [-.5, -.5] * samplingFrequency . ... The picture plots 3 times the filtered bandwidth to show the filter rolloff. ...

adapted from Observe: Eclipses, published in 1979 by the Astronomical League and "Safe Solar Filters," by B. Ralph Chou, Sky and Telescope, August 1981) . ... Tape TWO pieces of film together into a sandwich, and tape this over the opening in the cardboard. ... The cardboard frame will act as a shade from the bright Sun, while you safely observe through the film sandwich. ... Undeveloped film is not safe. ... tape . ... At the end of one of the tubes, tape the aluminum foil, and make a tiny pinhole. ...

Not on-site at APO, but can be obtained on loan--contact Jeff Morgan at UWash, morgan/astro.washington.edu . CENTER( ) PASSBAND( ) NEBULAR LINE (OR CONTINUUM) . 4861 60 Hbeta 5007 60 [O III] 6301 10 [O I] -- [S III]6312A line is supressed 6563 10 Halpha -- [N II]6584 and 6583 lines are suppressed 6583 10 [N II] -- Halpha line is suppressed 6728 80 [S II]6717+6731 4686 60 He II 4760 100 blue cont or Fe II 8290 195 red cont. See also the Hodge filter set below. ... APO Filters Homepage ...

Next: Cross References between CCF Up: Applications of CCF Previous: Applications of CCF Contents . Table 2: Cross reference of mirror CCF components to In-Flight Calibration Plan. Target Name . ... PSF . ... FilTransX, QuantumEf, XAreaEf . ... Table 3: Cross reference of EPIC CCF components to In-Flight Calibration Plan. ... Table 4: Cross reference of EPIC Inflight Calibration Targets to CCF components . ... Table 7: Cross reference of In-Flight Calibration Targets to OM CCF components . ...

Notes concerning the observations made by UKIRT for the YY Gem programme in March 1988. ... As spot modulation effects are relatively more prominent in V and flare effects in B, it was decided to monitor in K and V during eclipses and in K and B at out of eclipse phases. ... The data were corrected for extinction using the following extinction coefficients: B 0.27, V 0.10, K 0.07, J 0.10 . ... The following colour equations were derived for the UKIRT optical data using VISPHOT. ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

... FRAMES NO FRAMES All Classes . ... Classes in ij.plugin.filter that implement ExtendedPlugInFilter . ... Implements ImageJ's Subtract Background command. class . ... This plugin implements the Euclidean Distance Map (EDM), Watershed, Ultimate Eroded Points and Voronoi commands in the Process/Binary submenu. class . ... This plugin implements ImageJ's Process/Math submenu. class . ... This plugin implements the Mean, Minimum, Maximum, Variance, Median, Remove Outliers and Despeckle commands. class . ...

... Parameters . Filters . ... Direct images . ... The SCORPIO-2 project: . Spectral Camera with Optical Reducer for Photometric and Interferometric Observations - 2 . The broad-band glass filters made in SAO RAS are used for the observation in the Johnson-Cousins (UBVRI) photometric system in the direct images mode. The glass filters transmission curves are shown by solid line. ... The filters transmission curves of the `comets' filters measured with the SCORPIO-2 in the F/4 beam. ...

... Previous: Background Fluctuation Analysis from the Multiscale Entropy . ... A new measure of information is defined which is based on noise modeling and incorporates resolution scale. Properties of this measure are discussed. ... Additionally it allows for image noise modeling, and subsequent noise removal. ... Hence information- and entropy-based processing technologies will be necessary for the effective design and implementation of large, future generation, image databases. ...

Integration and performance of the flight configuration SIR on TELIS P. Yagoubov1, G. de Lange1, A. de Lange, M. Romanini, R. Hoogeveen1, V. Koshelets2, G. Wagner3, M. Birk 1Nation 3 al Institute for ... Netherlands 2Institute of Radio Engineering and Electronics, IREE, Russia 3Institute for Remote Sensing Technology, DLR, Germany Abstract TELIS (Terahertz and submm Limb Sounder) is a cooperation between European institutes, DLR, RAL and SRON, to build a three- ... LO frequency 624.93 GHz. ...

A computer controlled low light photometer for nightglow observations. Hardware units of portable photometer for low light measurements, especially night glow emission is described. ... Interface card contain three channels of 24 bit counter, 4 channels of 12 bit ADC and the buffer bus for the controlled motors of the altazimuthal fork mounting and filters wheel, the position encoders. ... Where N( ) is output signal photometer generated input light flux F( l ) . ... PMT # . 599 . ...

Wide-angle telescopes for photometry and polarimetry in optical and infrared ranges . ... Investigation of the Earth’s atmosphere, comets, interplanetary and interstellar medium with brightness and linear polarization measurements of extended sources and sky background in optical and infrared spectral ranges. ... The devices are small diameter telescopes with CCD-detectors for optical and infrared spectral range with spectral and polarization filters. ... 15-cm telescope with cooling down to 80 K . ...

... Tonight's Sky . ... The Magazine . ... Observing . ... Magazine . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... galaxies . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Astronomy for Kids . ... Maximize a minimum filter . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ... Astronomy Magazine . ...