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LSST System & Survey Key Numbers

This page lists Key Numbers that describe the LSST system and survey.

More details are available in the  LSST Knowledge Base Confluence page [1] (rendered here), the LSST Overview Paper [2] and Science Requirements Document [3].

See additional info and key numbers [1]

 

Telescope System:

  • Etendue ( AΩ ) : 319 meter2degrees2
  • Field of View : 3.5 degrees (9.6 square degrees)
  • Primary mirror diameter : 8.4 m
  • Mean effective aperture : 6.423 m (area weighted over FOV)
  • Final f-ratio : f/1.234
  • Camera weight : 6,746 lbs (3,060 kg)
  • Mirror (M1+M3 glass mirror only) weight : 35,900 pounds (16,284 kg)

Imaging System:

  • Pixel count : 3.2 Gpixels
  • Focal plane : 189 4kx4k science CCD chips
  • Pixel pitch : 0.2 arcsec/pixel
  • Pixel size : 10 microns
  • Filling factor : >90%
  • Minimum exposure time : 1 sec

Throughput:

  • 5-sigma point source depth: Single exposure and idealized for stationary sources after 10 years,  
  • u : 23.9,  26.1
  • g : 25.0,  27.4
  • r : 24.7, 27.5
  • i : 24.0 , 26.8
  • z : 23.3,  26.1
  • y : 22.1, 24.9

(https://smtn-002.lsst.io [4] : Calculating LSST limiting magnitudes and SNR)

spectral response/throughputs  [5]

[6]

The LSST bandpasses. The vertical axis shows the total throughput. The computation includes the atmospheric transmission (assuming an airmass of 1.2, dotted line), optics, and the detector sensitivity. For more details, please see the LSST overview paper [2].

Site Stats:

  • Median Atmospheric PSF with outer scale of 30m: 0.67” (Tokovinin)
  • Site: El Penon, Cerro Pachon, Chile
  • Site coordinates:  latitude -30:14:40.68  longitude -70:44:57.90
  • Altitude: 2647m
  • Site observatory code [7]: TBD
  • Photometric time: 53% of night time (estimated)

Observation Properties:

  • Standard visit exposures (expected) : 2 x 15 sec.
  • Median (Mean) visit time : 39s (42.2s)
  • Photometric accuracy : 10 mmag
  • Astrometric accuracy : 50 mas
  • Astrometric precision : 10 mas

Dataset properties:

  • Nightly data size: 20TB/night
  • Final database size (DR11) : 15 PB
  • Real-time alert latency : 60 seconds

Data Releases:

  • Survey duration : 10 years
  • Number of Data Releases : 11
  • Number of objects (full survey, DR11):
  • 20B galaxies
  • 17B resolved stars
  • 6M orbits of solar system bodies
  • Average number of alerts per night: about 10 million
Source URL: https://www.lsst.org/scientists/keynumbers

Links
[1] https://confluence.lsstcorp.org/display/LKB/LSST+Key+Numbers
[2] http://arxiv.org/pdf/0805.2366.pdf
[3] https://docushare.lsst.org/docushare/dsweb/Get/LPM-17/LSSTSRD_v5%202%203.pdf
[4] https://smtn-002.lsst.io
[5] http://github.com/lsst/throughputs/tree/master/baseline
[6] https://www.lsst.org/sites/default/files/f4-2.jpg
[7] https://www.minorplanetcenter.net/iau/lists/ObsCodesF.html