Technical Specs - Pathfinder and Atlas


The table below highlights some of the current expectations for the Pathfinder telescope and for the Atlas instrument itself. Pathfinder is a tech demonstrator intended to help guide the ATLAS software effort past Spiral 1 to Spiral 2.

THESE WILL EVOLVE!

Please contact us before using any of these specifications to check for updates.

 

Pathfinder

Atlas

Number of observatories/sites 1 Initially 2, goal 6 or more
Location Mauna Loa Mauna Loa and Haleakala in Hawaii. Additional sites desired in Australia, Chile, Canaries, South Africa.
Site separation NA 100 miles (160 km)
Number of telescopes per observatory 1 1
Telescope design Takahashi Epsilon-180 DFM custom Wright Schmidt
Telescope aperture 0.18m 0.5m
Telescope focal length 0.5m (f/2.8) 1.0m (f/2.0)
Telescope field of view 5.2° 7.4°
Telescope mount Equatorial APM German equatorial mount
Detector Two 2x4k MITLL CCID20 STA-1600, 10.5x10.5k CCD
Pixel size 15µm 9µm
Pixel scale 6.2" 1.86"
Effective PSF FWHM (assuming 1.5" seeing) 5" 2.5"
CCD operation temperature -60C -60C
Individual camera FOV 25 deg² 30 deg²
Total FOV 25 deg"sup2; 60 deg² for initial 2 sites
Nominal exposure time 30 sec 30 sec
Expected readout time 8 sec 6 sec
Filters and 5-sigma limiting AB magnitude per 30 sec exposure (stationary, solar spectrum, dark, ignore RN, SNR² average over FOV)
Filter
name
Bandpass
[nm]
m1
[AB]
sky
[AB/"²]
m5σ
[AB]
'open'400-82021.320.618.4
g 400-55019.921.918.4
r 560-69020.321.018.2
i 690-82020.420.117.6
Filter name Bandpass
[nm]
m1
[AB]
sky
[AB/"²]
m5σ
[AB]
'cyan' 420-650 22.8 21.2 20.5
'orange' 560-820 23.2 20.4 20.2
g 400-550 22.1 21.9 20.4
r 560-690 22.4 21.0 20.2
i 690-820 22.5 20.1 19.6
H-a 653-663 19.7 20.9 18.6
[OIII] 498-508 19.3 21.9 18.8
Photometric accuracy 0.01 mag @ r~14.0
0.02 mag @ r~15
0.04 mag @ r~16
0.01 mag @ r~16.0
0.02 mag @ r~17.2
0.04 mag @ r~18.
Saturation r ~ 11 r ~ 12.5
Astrometric accuracy ~6"/SNR where 2.5*log(SNR) ~ (20-m) ~2"/SNR where 2.5*log(SNR) ~ 22-m
Auxiliary cameras Canon 5D2, 135f/2 lens, 10x15 deg, mlim ~ 14 Canon 5D2, 135f/2 lens, 10x15 deg, mlim ~ 14
Survey coverage 5,000 deg² three times per night 20,000 deg² three times per night
Time between revisits each night About 30 minutes About 30 minutes
Total number of images per night per site 900 1000
Total data rate per site 35GB/night 150GB/night
Number of asteroid detections/night Up to 6,000 (i.e. 2,000 asteroids detected 3x each) Up to 75,000 (i.e. 25,000 asteroids detected 3x each)
Number of detected impactors/year 0 1
Impactor detection efficiency >60% for objects larger than about 150 meters diameter. Most of the remaining 40% are approaching from the direction of the Sun and can not be seen in the night sky. >60% for objects larger than about 50 meters diameter. Most of the remaining 40% are approaching from the direction of the Sun and can not be seen in the night sky.
Impact Warning Time About a week for 100 meter diameter impactor
About a month for a 500m diameter impactor
About a week for 50 meter diameter impactor
About a month for a 140m diameter impactor
Maximum asteroid detection distance:
(assuming 0.1 albedo and face-on)

1 meter diameter:
~100,000km ~ 0.3 lunar distance
~ 0.001 AU ~ 2 hour

10 meter diameter:
~1,000,000km ~ 3 lunar distance
~ 0.01 AU ~ 1 day

100 meter diameter:
~10,000,000km ~ 30 lunar distance
~ 0.1 AU ~ 1 week

1 meter diameter:
~ 0.4 million km ~ 1 lunar distance
~ 0.003 AU ~ 5 hour

10 meter diameter:
~ 4 million km ~ 10 lunar distance
~ 0.03 AU ~ 2 day

100 meter diameter:
~ 40 million km ~ 100 lunar distance
~ 0.3 AU ~ 3 week

Construction and development time About 3 months. We went online in Dec 2013 About 3 years. We should go on-sky in 2015 and begin regular operations in 2016
Development time for each additional observatory/site About 3 months About 18 months