Next: Antenna gain considerations and Up: Some theory Previous: Some theory . To provide correct flux density units for the visibilities, , from an interferometer, the measured correlation coefficient at the correlator ( ) needs to be scaled by a system temperature and a telescope sensitivity factor ( ). ... For a zenith opacity , observing at an elevation of , and if the atmosphere is approximated as having a uniform temperature , then the atmospheric contribution to system temperature is . ...

... ALMA | ... Currently I spend most of my time working on advanced phase calibration techniques and instrumentation for ALMA . ... I joined the team in April 2009 and started by looking at the effects of the dispersive path delay on phase correction (ALMA Memo 590) . ... We're currently analysing the copious quantities of WVR test data recently taken (Jan-March 2010) at the high ALMA site. 50% of my time is dedicated to the ALMA atmospheric temperature profiler. ... ALMA Site . ... 2010 Emily Curtis |...

The Cosmic Microwave Background Radiation Temperature Work in groups of 2-4. ... Due 1999 April 15 In this laboratory exercise, you will use the radio telescope on the roof of Science B to measure the intensity of the Cosmic Microwave Background Radiation (CMBR). ... The output of the telescope when pointing at the sky will then be 2 Tsys = Trec + Tsky : The temperature of the sky can in principle arise from two sources, radiation from the atmosphere and radiation from outer space (the CMBR). ...

... On-line calibration consists of calibration operations performed to maintain the ALMA observing system properly tuned to successfully execute the planned observations. ... Among processing operations are the calibration of the atmospheric absorption, of phase radiometric correction, of pointing scans, of phase and amplitude reference measurements, .. ... In the mean time tests of the calibration software will proceed using both simulated data and data from the antenna prototypes...?re 1 . ...

HIGH RESOLUTION IONOSPHERIC MASS SPECTROMETER P-11 . ... Onboard mass-spectrometric equipment for study of neutral and ionized components of Earth upper atmosphere. Mass-spectrometer P-11 is one of P-series modifications of the on board radio-frequency monopole spectrometers. ... The instruments of P-series have passed successful approbation in space experiments aboard geophysical rockets MP-12, launched for investigation of Earth upper atmosphere (Ref. ... Measured mass number range, AMU - 1.. ...

... Because of the Earth 's gravity, atmosphere is horizontally stratified (see, e.g., Kelley, 1989). Its structure can be organized by using the neutral gas temperature, as shown in the figure from mid-latitudes (note the logarithmic altitude scale). When going upward from the ground within the lowermost atmospheric region, troposphere, the temperature decreases up to about 10 km altitude (tropopause). ... Here the radiation also ionizes the neutral atmosphere, creating the ionosphere . ... 1989. ...

Next: Temperature and humidity Up: Observational data Previous: Comment field . Several other data are useful, or even essential. ... Additional instrumental parameters, like the size of the measuring aperture or the high voltage used on a photomultiplier, are essential and must be recorded for each observation if they vary. ... The Geneva quality-control parameters [ 3 ] may be available; again, they should have separate columns in the table. ... Temperature and humidity data . ...

In the PROJECT we are using the following peculiar . features of RATAN-600 . ... Brightness temperature sensitivity being equal to the antenna temperature sensitivity .. ... Receiver system .. ... Using aperture averaging effect. dual- beam and dual (multi-) frequency filtration, we demonstrated full filtration of the atmosphere noise down to the receiver noise at all scales of acoustics peaks ( Fig.1 , Fig 2 ). ... We select this frequency as the central one in our project. ... Antenna surface . ...

... I have stellar model atmosphere program which is available to anyone at STScI. The program employs a complete linearization technique to achieve convergence for plane parallel, LTE model atmospheres from which the emergent flux is computed and spectral line strengths can be evaluated. ... This program can be used to model stars over a very large region of the HR diagram, from cool white dwarf stars (Teff=5000K) to main sequence stars of spectral type A, and perhaps brown dwarfs. ... 3/24/1998 ...

... Electrode polarization measurements . ... Processing of ceramic materials, electrode systems and electrochemical cells . ... The technique is based on the measurements of a sample length variations with temperature or isothermal changes of the atmosphere, imploying the Linseis L75 vertical dilatometer. ... The gas system is equipped with a programmable gas-box, electrochemical oxygen pump and a sensor enabling to ajust and to continuously control the oxygen partial pressure in the range 10-21 - 1...

... Blue Saturn . ... The image has been adjusted to approximate the natural blue color of visible sunlight scattered by the gas giant's upper atmosphere. ... This strange, false-color image of otherwise familiar planet Saturn shows temperature changes based on thermal infrared emission in the gas giant's atmosphere and rings. ... Heat Shield Impact Crater on Mars . ... Not everything seen on the night sky is understood. ... NGC 3132: The Eight Burst Nebula . ... The Radio Sky: Tuned to 408MHz . ...

Next: Quantum Efficiency Correction (a.k.a. Up: ROSAT HRI Recipes Previous: Appearance of new HRI . The mean pulse height analyzer channel (PHA) of a spectral distribution will vary depending on its location on the detector. Below is a method to compare observed data with that of preflight calibration measurements. ... For temporal gain variations, see The HRI Calbration Report . ... Retrieve the gain maps (mean PHA) from anonymous ftp at SAO. ... But don't forget temporal gain variations!] ...

... The ultraviolet properties of seventeen extreme helium stars have been examined using 150 IUE spectra. ... In most cases, these were in good agreement with previous measurements, but there are some ambiguities in the case of the hotter stars, where the solutions for Teff and E_bv become degenerate, and in the case of the cooler stars with large E_bv, where the total flux is no longer dominated by the ultraviolet. ... Subsequently, measurements of the stellar radii and distances could be derived. ...

... The Science Operation Department is composed of Astronomers, Telescope Instruments Operators(TIOs) and Data Handling Administrators(DHAs). ... Astronomers have proposed several methods to quantitatively measure the amount of turbulence above the telescope, which the most common ones is Differential Image Motion Monitor (DIMM). In optical testing, the Hartmann test is the common method to test the quality of optical components. ... Hartmann mask consists of 48 lenses. ...

... Calibration and sensitivity measurements for tests of microwave radiometers. ... The instrument consists of two waveguide matched loads operating at ambient temperature and two matched loads, cooled at variable temperatures. The temperatures are microprocessor-controlled. The test version of instrument is available. ... Dimensions                                          450 350 550 mm . ... Output temperature                                            100–350 й . ...

... Preliminary analysis of early data returned by NASA's historic Galileo probe mission into Jupiter's atmosphere has provided a series of startling discoveries for project scientists. ... These initial findings are encouraging scientists to rethink their theories of Jupiter's formation and the nature of planetary evolution processes, according to probe project scientist Dr. Richard Young of NASA's Ames Research Center, Mountain View, CA. ... GIF, 29K ) . ... Structure of Jupiter's Atmosphere . ...

... Доклады предсталенные во время летней школы 'Atmosphere researches. Challenge for Ukraine", прошедшей с 15 по 19 сентября 2008 г. за поддержки Швейцарского национального научного фонда (JRP #?В7320-110831) . ... Introduction into Particulate matter research: Measurement techniques, formation, influence on air quality and climate. ... Ozone formation in the troposphere: Basic mechanisms and photooxidant air pollution. ... Atmosphere researches. Challenge for Ukraine' . ... 380(44)5264539 . ...

Operating of the superconducting integrated receiver channel of the TELIS atmospheric sounder. ... The noise temperature of the SIR was measured to be as low as 120 K, with an intermediate frequency band of 4 ­ 8 GHz in double sideband operation; the spectral resolution is well below 1 MHz. The SIR was implemented in the three-channel balloon-borne instrument TELIS (TErahertz and submillimeter LImb Sounder) that detects spectral emission lines of stratospheric trace gases (like ClO and BrO). ...

... They are concerned with Attitude Control System of the spacecraft, satellite visibility from tracking stations, limits on the satellite autonomous operations during the orbit, and needs for auxiliary operations with the spacecraft. ... Among the operational constraints the most important one is the number of programmed slews per orbit, which determines the maximum number of radio sources to be observed during one orbit. ... System temperature (K) . ... Progress of the RadioAstron Project in Pictures...

... More on 51 Peg: . The discovery of a Jupiter--mass planet in orbit around the solar--type star 51Peg has been reported by Michel Mayor and Didier Queloz (Geneva Observatory) on October 6th at the 9th Cambridge workshop on "cool stars, stellar systems, and the sun" held at Florence (Italy). ... Recall that the measurements of radial velocity only yield v sin i which in turn gives us M sin i. For most values of i, sin i will be greater than 0.5 and this gives a mass estimate of 0.5 Jupiter masses. ...