LSST System & Survey Key Numbers

This page lists Key Numbers that describe the LSST system and survey.  More detailed information is available in the LSST Overview Paper and Science Requirements Document.  (Page last updated 1/22/15)


Etendue ( AΩ ) = 319 meter2degrees2
Field of View =  3.5 degrees (9.6 square degrees)
Effective clear aperture =  6.68m (including obscuration)
Final f-ratio =  f/1.234
Primary mirror aperture =  8.4 m
Pixel count =  3.2 Gpixels
Readout time =  2 sec
Dynamic range =  16 bits
Plate scale =  50.9 microns/arcsec
Filter set full bandpass range = 320-1050 nm                

Number of active filters =  5
Real-time alert latency =  60 seconds
Fiducial number of visits per pointing in the main survey = 825
Fiducial main survey area = 18,000 deg2
Estimated total covered area, including special programs = 25,000 deg^2
Number of

visits collected over 10 years = 2.75 million
images collected in 10 years = 5.5 million
visits per night = "about a 1000"
calibration exposures = 450/day
data collected per 24 hr period = "about 15 TB"

Standard visit exposure duration = 15 s
Time to take a single exposure = 18 s
Median slew time between visits = 5 s
Time to take one visit in normal survey mode

Median = 39 s
Mean  = 44 s

Estimated number of objects in DR11= 37 billion
Estimated number of single-epoch sources in DR11= 7 trillion
Estimated number of forced measurements in DR11= 30 trillion
Estimated numbers for DR1 release

Objects = 18 billion
Sources = 350 billion
ForcedSources = 0.75 trillion

Average number of alerts per night= "about 10 million"
Network bandwidths

Summit (Pachón) to Base (La Serena) =  2 x 100 Gbps
Base(La Serena) to Archive (NCSA) = 2 x 40 Gbps

Data and compute sizes      

Final image collection (DR11) = 0.5 Exabytes
Final database size (DR11) = 15 PB
Final disk storage = 0.4 Exabytes
Peak number of nodes  = 1750 nodes
Peak compute power in LSST data centers = 1.8 PFLOPS

Number of Data Releases = 11
Date of DR1 release = Date of Operations Start+ 12 months