DETECTING NEAR EARTH OBJECTS
The OMI with its large field-of-view (FOV) of 5 degrees²
and its deep limiting magnitude is well positioned to detect near
Earth Asteroids (NEA's) that may threaten our civilization. These
objects move very fast and are very dim thus making THEM very
difficult to detect. The key to detection is to survey large areas
of the sky as quickly and deeply as possible. The fainter the
objects than can be detected, than smaller and further out the
objects than can be detected.
|
Program
|
OMI
|
Spacewatch
|
Spacewatch
|
NEAT
|
NEAT
|
LEONOS
|
LINEAR
|
CSS
|
BISEI
|
|
Aperture(m)
|
1.0
|
0.9
|
1.8
|
1.2
|
1.2
|
0.6
|
1
|
0.68
|
0.5
|
|
f number
|
2.5
|
3
|
2.7
|
1.9
|
2.5
|
1.9
|
2.2
|
1.9
|
1.9
|
|
Telescope type
|
prime
|
prime
|
folded
|
prime
|
Schmidt
|
Schmidt
|
folded
|
Schmidt
|
Cass.
|
|
Array Dimensions
|
10580x10560
|
2048x4603 x4
|
2048x2048
|
4080x4080
|
4080x4080x3
|
2048x2048x2
|
1960x2560
|
4096x4096
|
2048x2048x2
|
|
Pixel size (um)
|
9
|
13.5
|
24
|
15
|
15
|
13.5
|
24
|
15
|
15
|
|
Pixel size (arcsec)
|
0.76
|
1
|
1
|
1.4
|
1
|
2.5
|
2.25
|
2.5
|
3.2
|
|
FOV (deg)
|
4.94
|
2.9
|
0.3
|
2.5
|
3.8
|
8.3
|
2
|
8.3
|
3.1
|
|
Cooling (ºC)
|
-100
|
-90
|
-90
|
-20
|
-40
|
-130
|
-50
|
-100
|
-100
|
|
Readout mode
|
stare
|
stare
|
ds/stare
|
stare
|
stare
|
stare
|
stare
|
stare
|
stare
|
|
CCD type
|
thin
|
thin
|
thin
|
thick
|
thick
|
thin
|
thin
|
thick
|
thin
|
|
Exposure (sec)
|
48
|
120
|
150
|
20
|
60
|
45
|
5
|
30
|
23
|
|
Magnitude Limit
|
23v
|
21.7
|
22.64
|
19.5
|
21v
|
19.3v
|
19.2
|
20v
|
19
|
|
Coverage (deg²/h)
|
300
|
29
|
7.4
|
174
|
174
|
400
|
1050
|
194
|
|
|
Number of visits
|
3
|
3
|
3
|
3
|
3
|
4
|
5
|
4
|
|
|
NEA discovered
|
|
584
|
440
|
289
|
2089
|
1584
|
180 (other)
|
|
NEA discovered/yr
|
|
42
|
31
|
21
|
149
|
113
|
10 (other)
|
|
Current NEO programs compared to a potential
OMI program (table adapted from Near-Earth Asteroid Search
Programs, Stokes, Larson, Uni. Arizona).
|
The OMI is well extremely well positioned compared to existing
NEA surveys. OMI will have significant one-site computing power
to permit real time image analysis and data extraction.
|
Mag r'
|
Exp. (s) s/n=3
|
Exp. (s) s/n=10
|
Exp. (s) s/n=50
|
|
19
|
0.27
|
1.46
|
29
|
|
20
|
0.73
|
4.5
|
97
|
|
21
|
2.21
|
17.4
|
405
|
|
22
|
8.5
|
81
|
2013
|
|
23
|
43
|
456
|
11,275
|
|
24
|
247
|
2710
|
68,351
|
|
25
|
1526
|
16,755
|
422,641
|
|
26
|
9,435
|
105,672
|
-
|
|
27
|
59,505
|
666,463
|
-
|
|
Anticipated limiting magnitude vs. exposure
|
|
