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VISTA performance

Details from VISTA fact sheet (2009 Sept 9)


Pixel scale:                                                         0".34 /pixel average
Best image quality achieved:                             0".6 including seeing, optics and sampling
Image distortion:                                                <15% of PSF in the corners of the field
Estimated image quality PSF of 0".51               Paranal seeing convolved by the instrument PSF of 0".51
Photometric calibration:                                    +/- 2% RMS in respect to 2 MASS in J, H, Ks
Photometric calibration:                                    +/- 2% internally
Sky concentration/illumination:                        <5% absolute, it can be characterized and corrected down to 2% RMS.
Filter set:                                                             Z, Y, J, H, Ks, NB118 - all filters are installed
Detector:                                                             Raytheon VIRGO HgCdTe arrays, sensitive over 0.84 - 2.5 micron wavelength region   
                                                                            high quantum efficiency, large number of hot pixels, some dead areas on detector 1

The system characterization and organization of the calibration strategy will be continued during the science verification and until the end of
Paranalization and Dry Runs phase.

Observation overheads:

Preset:                                                                 approximately 120 seconds
Preset:                                                                 20 secs + (target distance)/slew-speed where slew speed is 1 deg per second
Readout:                                                              2 secs per DIT
Write data to disk:                                               4 seconds per exposure
Filter change:                                                      21 seconds to 40 seconds (depending on relative filter location)
Jitter offset:                                                          approximately 3 seconds (same guide star)
Pawprint change:                                               10 seconds (changed guide star)

Detailed information about VISTA and VIRCAM can be found at:

Phase 2 tools (SADT and p2pp) can be downloaded from:

For further help contact