... The dark signal is exposure time dependent. The one appropriate for a given observation has to be derived by interpolation between dark frames of different exposure times. ... Bias and dark signal will usually be determined and subtracted in the same step. In a CCD with good cosmetic properties, bias and dark signal љ љ are the same for all pixels. ... If, because of local variations, this is not possible, some suitable smoothing should still be attempted. ... Tue Mar 28 16:52:29 MET DST 1995 ...

FGS Instrument Handbook for Cycle 24 . ... Fine Guidance Sensor Instrument Handbook for Cycle 24 > Chapter 7: FGS AstrometryData Processing > 7.2 Exposure-Level Processing . ... 7.2.2 Observing Mode Dependent Processing . ... After pipeline initialization and data quality assessments, successful observations (i.e., those that acquired the target), are processed according to the FGS observation mode: Position or Transfer. ... The corrections applied to the FGS data are as follows: . ... Transfer mode . ...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

Atmospheric influence on the different radio-engineering system functioning . ESTIMATION OF ATMOSPHERIC OPTICAL CHARACTERISTICS AND REMOTELY SANSED IMAGE CORRECTION . ... Direct transmittance estimation results for 12 channels of the spectrometer CHRIS. ... We have managed to develop a direct method of estimating the discrete Normalized Atmospheric Point Spread Function (NAPSF) from available images alone, not using any external sources of information about the atmosphere. ... IRE RAS 1996-20 11 ...

... The most precisely determined characteristic for accreting neutron stars (NS's) is their period. ... Period changes show fluctuations. ... Some applications of stochastic processes in astrophysics especially in accreting systems were discussed in Lipunov (1987),Hoshino Takeshima (1993) and Lipunov (1992).In Hoshino Takeshima (1993) the authors, using simple models of MHD turbulence, try to explain aperiodic changes in X-ray luminosity of X-ray pulsars. ... Here, -constant angular momentum. ...

... They were determined as a result of orbit improving on the base of all kinds of optical observations available in the catalog of observations of the Minor Planet Center on March 16, 2014 (radar observations have not been used at this stage). ... As the MPC orbits do not all were improved simultaneously with EMP orbits, only 383866 sets of elements were used for data comparison (for selected sets of elements process of improvement had started with the use of the same observations). ...

... the time of observation . ... Observing the Changing Position of the Sun To Establish Cardinal Directions . ... Observations of the Sun's apparent movement across the sky and its pattern of rising and setting in the east and west horizon helped to establish the cardinal directions. ... The final stage of the Sun's return was marked by the observation that the Sun had reached its highest altitude when the full width of your mitted hand could fill the gap between the Sun and the horizon. ...

Next: Filtering ROSAT HRI data Up: ROSAT HRI Recipes Previous: Correlating Spectral Data with . Although the spatial variation of the quantum efficiency across the HRI is nominally within 10% for most of the detector, occasionally it may be desirable to flat-field a map with preflight calibration measurements. ... Store the new gain map image using ``blink" in SaoImage. ... The quantum efficiency correction (QEC) is the inverse of the intensity determined from the QE map at the source position. ...

... TPMODE is an obsolete parameter since tape is no longer used. ... TPMODE=1 is appropriate for Mark III mode A, while TPMODE=2 is used for Mark III mode B. Setups with different values of TPMODE may be specified for a station during an experiment, but SCHED will determine the lowest value specified for the station for the whole experiment and use that for all scans. ... The correct TPMODE can be determined from the FORMAT , the number of bits per sample ( BITS ), and the number of channels ( NCHAN . ...

... We have developed an integrated system that performs astronomical observations in Near Infrared bands operating two-dimensional instruments at the Italian National Infrared Facility's ARNICA and LONGSP . ... The user interface is organized as widget-based X11 client. ... 1993; Di Giacomo et al. 1993). ... Moreover, if the interprocess communication interface includes support for networking, the software immediately becomes network distributed software. ... DESQview/X User Guide 1993, Quarterdeck . ...

Cosmic ray intensities (left) compared with predictions (right) from IBEX. The similarity between these observations and predictions as evidenced by the similar color regions supports the local galactic magnetic field direction determined from IBEX observations made from particles at vastly lower energies than the cosmic ray observations shown here. The blue area represents regions of lower fluxes of cosmic rays. ...

... In the pn-CCD, 768 individual amplifiers allow fast readout, but imply different gains for the different readout channels which all have to be determined and corrected for. The gains of the 768 readout nodes were derived by comparing the position of CTI corrected calibration lines (in adu) with their known energy. ... More details on the CTI and gain correction can be found in []. ...

Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

... Let us first find out which way -- rise in spectral resolution with some loss in the S/N ratio or increase in the S/N ratio with a fixed spectral resolution -- is better for the purpose of reduction of equivalent width determination errors. ... N -- number of counts for 1 ? ... line equivalent width, . ... Thus if the spectral resolution is managed to be increased (i.e. to decrease )without loss in the number of counts falling at 1 ?, the equivalent width measurement error is then proportional to . ...

RTT150 . ... This search system is designed for generating the necessary information on series of pointings (observations of each source consist of sets of exposures with different filters and sometimes with different exposure times) for observed sources. Search results appear at the separate page as a table with the following data: . DATE - real (not evening!) observations date (in YYYY-MM-DD format); . ... Bin - minimal CCD binning mode (may vary during the observations); . ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

IBIS Data Analysis . ... IBIS . ... Flat Fielding - Introduction . The images obtained by IBIS will have intensity variations across the field of view that are not due to the solar image, but rather caused by instrumental effects that alter the observed intensity in each point of the field of view. ... IBIS Flat Fielding Techniques . ... Therefore, it is desirable to obtain the flat field measurements center on a point along the equator near the heliographic center of the solar disk. ...

... Plots of the 4 wapps (.ps) ( .pdf ) : . ... top plot: this is how many seconds off the wapp clocks were measured to be from the ntp servers on the network. The colors are for the 4 wapps. 2nd plot: This is the offset (in seconds) that the ntpd pll time loop was using. ... Notice that there are no changes from 9.06 till 9.31 when the loop parmeters were reset. 2nd plot: The frequency offset used in the wapp4 pll loop. 3rd plot: The time offset of wapp4 time relative to the 3 primary ntp servers. ...

Institute of Applied Astronomy Russian Academy of Sciences Method of Determining the Orbits of the Small Bodies in the Solar System Based on an Exhaustive Search of Orbital Planes Dmitrii Vavilov, Yurii Medvedev Introduction to the problem: Let we have n 3 positional observations of a body: points in time ( = 1, ) , right ascensions , and declinations . ... Determination of the orbit using the Gauss method of determining orbital elements based on two heliocentric positions and points in time. ...

... Images obtained using the Faulkes Telescope South, operated by Las Cumbres Observatory. ... The Faulkes Telescope Project and Las Cumbres Observatory Global Telescope Network had kindly given us the opportunity to use these telescopes and the observatory had booked us four sessions of controlling the telescope in order for us to make some observations on NEOs. ... Just before our first observing session on Friday, we were given a tour of the observatory building and its telescopes, by John McFarland...