Visible and Infrared Survey Telescope for Astronomy. News: 2. 4/1. 0/2. UK Channel 4 News (7. VISTA's 8. 4 million stars (mp. VISTA creates huge 9 Gpixel zoomable image of 8. STFC press release)2. VISTA creates largest ever catalogue of centre of our galaxy. Building VISTAPhotos of VISTAImages taken with VISTA2. Ultra. VISTA press release. Old news. Overview - for potential users. VISTA is a 4- m class wide field survey. VISTA's nominal pixel size) containing 6. Z,Y,J,H,Ks and a narrow band filter at 1. A wide field visible camera. VISTA. The telescope has an azimuth- altitude mount, and quasi- Ritchey- Chretien. Cassegrain. The instrument mounts to the rotator. VISTA is located at ESO's Cerro Paranal Observatory. Chile (latitude 2. Seeing, and other weather realted statistics. Cerro Paranal are given at ESO's Astroclimatology. Paranal pages and the VISTA site is expected to have similar. The site, telescope aperture, wide field, and high quantum efficiency. VISTA the world's outstanding ground based near- IR. Time available. 75% of the VISTA time available to ESO will be available for large. On the assumption that VISTA is unavailable ~1. Public Surveys: ~2. Proprietary Surveys: ~7. Nights. In planning surveys it should be realised that the surveys as a. RA range. One of the roles. Public Survey Panel for VISTA will be to ensure that the. Public surveys form a realistic set in the light of these. Information on the conditions at the Cerro Paranal Observatory. Utilities and SDK for Subsystem for UNIX-based Applications in Windows Vista, Windows Vista SP1, and Windows Server 2008. Vista Technology Inc. Founded in Edmonton, Alberta Canada in 1976 as a Prepared Microbiological. We carry a full range of replacement parts for blinds shades and drapes. Welcome to Vista Products: Explore the best in Designer Window Coverings. Home; Our Company; Contact Us; Dealer Login. Dealer Login. ESO Astroclimatology. Paranal pages. For all observing time at ESO telescopes ESO assume 1. April to 3. 0 September). October to end of February). These numbers are used at submission time as approximate indications. Filters. Filterplot. Laser toner and inkjet cartridge remanufacturing parts and supplies, online training and support from leading manufacturer and distributor Static Control. The Electronic Components and Technology Conference (ECTC) is the premier international event that brings together the best in packaging, components and. How to Install iTunes on Windows Vista. Windows Vista is no longer a supported operating system for iTunes. You'll need to use a special installer from Apple for an. Windows Vista, a major release of the Microsoft Windows operating system, was available in six different product editions: Starter, Home Basic, Home Premium, Business. Wavelength. FWHMComment at 2. Kmicron Ztransmission. Ytransmission. 1. Jtransmission. 1. Htransmission. 1. Kstransmission. 2. NB1. 1. 8plot to be provided. The only moving part in the camera is the filter wheel. With the. current complement of Z, Y, J, H, Ks and NB1. Purchase of other filters are under discussion by various groups. VISTA. twiki filters page. Field Distortion. The plate scale varies with distance from the field centre, getting larger from centre to edge, which is why the mean pixel size (of 0. The rectangular focal plane, when projected onto the sky, suffers barrel distortion. This means that a somewhat larger area of sky is seen by the detectors than if there was no distortion. A rectangular area of sky when imaged onto the focal plane suffers from pincushion distortion. Covering an area of sky. The sixteen 2. 04. IR detectors (Raytheon VIRGO Hg. Cd. Te. 0. 8. 4- 2. Z- axis which on the telescope points towards. On the sky (in the default instrument rotator position). Y corresponds to N, and +X to East. Below - photograph of the real focal plane. A single Integration of. DIT secs (or a coadded series of these known as an Exposure) produces a sparsely sampled image of the sky known as a Pawprint (in red in the following Figure). The area of sky covered by the. For comparison the fields. NICMOS, ISAAC, HAWK- I and WFCAM are shown below in Figure. This corresponds to 1. VISTA's mean pixel size. There is also a strip at the top and another at the bottom which is only covered once by this tiling pattern. These strips are each 0. This corresponds to 1. VISTA's nominal pixel size. The 3 steps in Y are then repeated at the nex position in X. So after 3x. 2=6 steps an area of 5. Assigning. only one of the two 0. Each position of a jitter pattern can contain. To better sample the PSF a Microstep. Due to distortion, microsteps. The calibration. software will not handle larger microsteps. Guide stars, wave- front sensor stars, survey area definition. Each integration requires a guide star for the autoguider to use. For a given sky area specified with respect to a sky position a. Survey Area Definition Tool (SADT) will lay down the appropriate. P2. PP) the. Observation Blocks (OBs). This tool is not needed to define a VISTA. Phase II in time for use. Estimating On Source Observing Time. For estimating required exposure times the Exposure Time Calculator. ETC) is given an object of a given magnitude for which it can determineeither a) the signal to noise achieved in a given exposure time or b) the exposure time needed to achieve a given signal to noise see Exposure Time Calculator description. ETC. Estimating Overheads. As with any telescope there are overheads associated with observing. Overheads making a single tile in one filter. Overheads on a tile depend on the adopted combination, and order. As an example. a typical minute spent on the sky in a fixed filter such as Ks might. The 'Observing Strategy' section in 'Observing Setup' section of. Exposure Time Calculator allows you to break a total on- source. Ndit of individual Integrations. DIT seconds long, with the Ndit*DIT long Exposures repeated Nexp times with a number of jitters, Njitter, and if required. Nx. M microstep pattern. The ETC then returns the total on sky time. Exposure Time Calculator description. Filter changes may be done in parallel with a position. Tile change overheads (not in ETC)There are three components to the time taken to go from one tile to another. Slewing/presetting in Az and Altii) Acquiring the guide stariii) Low order wavefront sensing (LOWFS) observation to update M2 positioneach of which is addressed in turn belowi) The time to go to a new tile will depend on how far away it is in altitude and azimuth from the current position, and on the zenith distance. As for any alt- azimuth telescope at VISTA’s latitude one wants to minimise presets between objects with Dec < - 2. Both alt and azimuth can accelerate at 0. The Cassegrain rotator is faster (1. Fortunately a more “typical” case at alt = 6. Assuming an acceleration of 0. These situations should be avoided, if at all possible, during scheduling. Checking and acquiring the new guide star will impose a short overhead of ~1 second. All these numbers will be updated when there is sufficient experience with the on- sky behaviour of the real system. Active Optics overheads (not in ETC)A Low Order Wavefront Sensor (LOWFS) is used to update the position of the secondary mirror during observations, and needs data for a minimum time of ~3. The LOWFS can operate in parallel with science observations. If the telescope is staying in one position for > /= ~3. LOWFS exposures merely start just after and finish just before the science integrations finish. However using the LOWFS in this basic mode implies a minimum time between jitter moves of ~3. With experience on sky we will learn that after tracking the same sky area for X minutes one needs to do an LOWFS update. The value of (probably X~1. In case that image quality falls off more quickly, or that one wants to observe for longer than X minutes before presetting to a new part of the sky, the telescope would by have to stay where it was with the camera idle until the LOWFS has accumulated enough (~ 3. As an alternative the AO control system could be changed to internally coadd LOWFS frames to give the necessary exposure from shorter exposures with the star moving on the chip between exposures. This mode remains to be implemented and will then need to be tested on sky.
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