Table I
Infrared Background Specification
| SIRTF | CRDG: Contamination Requirements Definition
Group |
---|
|
|
|
---|
λ (μm) | NEP in 10 μm band 1 arc min FOV | Time variation of background | Angular variation of background | Time variation of background | Angular variation of background | Max. Background intensity |
---|
| | W | W | W | W | W |
---|
| |
|
|
|
|
|
---|
| W/Hz1/2 | sec (arc min)2 10 μm | deg 10 μm (arc min)2 | sec μm sr m2 | deg μm sr m2 | μm sr m2 |
---|
5 | 1 × 10−17 | 2 × 10−17 | 4 × 10−17 | 5 × 10−17 | 1 × 10−10 | 7 × 10−9 |
10–30 | 1 × 10−17 | 2 × 10−17 | 4 × 10−17 | 5 × 10−11 | 1 × 10−10 | 1 × 10−8 |
30–300 | 1 × 10−16 | 2 × 10−16 | 4 × 10−16 | 5 × 10−10 | 1 × 10−9 | 1 × 10−7 |
Table II
6.27-μm Emission from H2O
| | | Power on detector (W) |
---|
| | |
|
---|
| | | +Z L.O.S. | 50° + X L.O.S. | 50° + Y L.O.S. |
---|
Offgassed H2O after 24 hr |
Position 1 |
| column density (cm−2) | 8.7(11) | 7.0(11) | 6.3(11) |
power on detector (W) | 1.8(−14) | 2.3(−14) | 1.3(−14) |
Position 2 |
| column density | 4.0(10) | 3.6(10) | 4.0(10) |
power on detector | 9.0(−16) | 9.2(−16) | 9.8(−16) |
Position 3 |
| column density | 3.3(11) | 2.2(11) | 4.0(10) |
power on detector | 7.5(−15) | 7.0(−15) | 9.8(−16) |
Contribution from cabin leakage |
| column density | 1.3(11) | 5.5(11) | 1.3(11) |
power on detector | 1.1(−15) | 4.5(−15) | 1.1(−15) |
Contribution from evaporators for position 1 |
| column density | 9.5(11) | 1.8(11) | 4.2(12) |
power on detector | 1.1(−14) | 3.5(−15) | 4.1(−14) |
Position 1 has the top side of the Shuttle Orbiter and the entire Payload Bay facing the sun.
Position 2 has the top side of the Shuttle Orbiter and the Payload Bay facing away from the sun
and the earth, but the bottom side of the Orbiter is facing the sun.
Position 3 has one side of the Shuttle Orbiter facing the sun but the Payload Bay is shaded. The
50° + Y L.O.S. is looking away from the sun.
Table III
Rotation Line Emission from H2O
| Wavelength range | Power on detector (W) |
---|
|
---|
+ Z L.O.S. | 50° + L.O.S. | 50° + Y L.O.S. |
---|
Offgassed H2O after 24 hr | | | | | |
Position 1 |
| 10–20 μm | 5.2(−15) | 5.0(−15) | 4.9(−15) |
20–30 μm | 3.0(−14) | 3.1(−14) | 2.3(−14) |
30–40 μm | 6.5(−14) | 6.1(−14) | 4.7(−14) |
40–50 μm | 5.0(−14) | 4.3(−14) | 3.6(−14) |
Position 2 |
| 10–20 μm | 1.5(−15) | 1.5(−15) | 1.5(−15) |
20–30 μm | 1.5(−15) | 1.5(−15) | 1.5(−15) |
30–40 μm | 2.0(−15) | 2.0(−15) | 2.2(−15) |
40–50 μm | 1.7(−15) | 1.7(−15) | 1.8(−15) |
Position 3 |
| 10–20 μm | 1.8(−15) | 1.7(−15) | 1.5(−15) |
20–30 μm | 8.2(−15) | 7.3(−15) | 1.5(−15) |
30–40 μm | 2.0(−14) | 1.5(−14) | 2.2(−15) |
40–50 μm | 1.7(−14) | 1.2(−14) | 1.8(−15) |
Contribution from cabin leakage |
| 10–20 μm | 4.8(−16) | 1.0(−15) | 4.8(−16) |
20–30 μm | 2.6(−15) | 1.0(−14) | 2.6(−15) |
30–40 μm | 7.4(−15) | 3.1(−14) | 7.4(−15) |
40–50 μm | 6.4(−15) | 2.7(−14) | 6.4(−15) |
Contribution from evaporators for position 1 |
| 10–20 μm | 6.0(−15) | 5.5(−15) | 8.4(−15) |
20–30 μm | 1.8(−14) | 3.2(−15) | 7.0(−14) |
30–40 μm | 5.0(−14) | 1.0(−14) | 2.2(−13) |
40–50 μm | 4.4(−14) | 8.7(−15) | 2.0(−13) |
Table IV
Number of Particles Passing Through a 1 min of arc Field of View per Second for a 1-m Diam
Telescope 3 m Long
| Initial velocity (cm/sec) |
---|
Particle radius(μm) | 5 | 10 | 30 | 50 |
---|
2 | 0 | 0 | 0.0050 | 0.0097 |
3 | 0 | 0 | 0.0077 | 0.0093 |
5 | 0 | 0 | 0.0097 | 0.0095 |
10 | 0 | 0 | 0.0096 | 0.0079 |
40 | 0 | 0.0094 | 0.0077 | 0.0058 |
160 | 0.0094 | 0.0089 | 0.0058 | 0.0053 |
640 | 0.0089 | 0.0063 | 0.0051 | 0.0053 |
Table V
Dust Particle Results when Integrated over the Particle Size Distribution for a 1 min of arc
Field of View
V0 (cm/sec) | No. of particles/sec in field of view | Fraction of time a particle is in the field of view | Average time in field of view for each particle (sec) |
---|
5 | 4.4 (−6) | 1.3 (−5) | 2.9 |
10 | 9.2 (−5) | 1.3 (−4) | 1.4 |
20 | 2.4 (−3) | 1.6 (−3) | 0.7 |
30 | 7.5 (−3) | 4.2 (−3) | 0.6 |
50 | 9.3 (−3) | 5.9 (−3) | 0.6 |
all velocities | 2.6 (−3) | 1.6 (−3) | 0.6 |
Table VI
Fraction of Time that Chopping Cancels the Effect of Particles in the FOV as a Function of
Blurred Image Size and Chopper Throw
Image size ÷ F.O.V. | Chopper throw ÷ field of view |
---|
| 1 | 2 | 3 | 4 |
---|
1 | 0.17 | 0 | 0 | 0 |
2 | 0.25 | 0.10 | 0 | 0 |
3 | 0.40 | 0.17 | 0.07 | 0 |
4 | 0.50 | 0.29 | 0.125 | 0.06 |
6 | 0.56 | 0.44 | 0.30 | 0.18 |
8 | 0.70 | 0.55 | 0.42 | 0.31 |
16 | 0.83 | 0.74 | 0.65 | 0.57 |
32 | 0.91 | 0.86 | 0.81 | 0.76 |
64 | 0.96 | 0.93 | 0.90 | 0.87 |
128 | 0.98 | 0.96 | 0.95 | 0.93 |
256 | 0.99 | 0.98 | 0.97 | 0.97 |
500 | 0.99 | 0.99 | 0.99 | 0.98 |
1000 | 0.99 | 0.99 | 0.99 | 0.99 |
Table VII
Probability that a Dust Particle Will Have a Certain Image Size in a 1-m Telescope as a Function
of Initial Velocity V0 and Particle Radius
rd
V0 (m/sec) | rd (μm) | Image size (min. of arc) |
---|
<1 | 1–2 | 2–4 | 4–8 | 8–16 | 16–32 | 32–64 | 64–128 | 128–256 | 256–1000 | >1000 |
---|
0.05 | 80 | | | | | | | | | | 0.747 | 0.253 |
0.05 | 320 | | | | | | | | | | 0.945 | 0.055 |
|
0.1 | 20 | | | | | | | | | | 0.747 | 0.253 |
0.1 | 80 | | | | | | | | | | 0.945 | 0.055 |
0.1 | 320 | | | | | | | | | 0.287 | 0.691 | 0.021 |
|
0.3 | 2.1 | | | | | | | | | | 0.675 | 0.325 |
0.3 | 10 | | | | | | | | | | 0.900 | 0.100 |
0.3 | 40 | | | | | | | | | 0.331 | 0.626 | 0.043 |
0.3 | 100 | | | | | | | | 0.167 | 0.471 | 0.337 | 0.025 |
0.3 | 316 | | | | | | | 0.288 | 0.268 | 0.202 | 0.234 | 0.007 |
|
1.0 | 5 | | | | | | | | | 0.474 | 0.493 | 0.032 |
1.0 | 10 | | | | | | | | 0.277 | 0.405 | 0.298 | 0.020 |
1.0 | 32 | | | | | | | 0.353 | 0.225 | 0.185 | 0.230 | 0.007 |
1.0 | 100 | | | | | 0.129 | 0.343 | 0.087 | 0.085 | 0.137 | 0.197 | 0.022 |
1.0 | 316 | | | | 0.356 | 0.142 | 0.046 | 0.046 | 0.095 | 0.116 | 0.184 | 0.015 |
|
3.0 | 10 | | | | | 0.023 | 0.440 | 0.106 | 0.076 | 0.137 | 0.197 | 0.022 |
3.0 | 32 | | | | 0.321 | 0.154 | 0.061 | 0.064 | 0.077 | 0.125 | 0.184 | 0.015 |
3.0 | 100 | | 0.185 | 0.230 | 0.101 | 0.018 | 0.035 | 0.043 | 0.083 | 0.117 | 0.174 | 0.014 |
3.0 | 316 | 0.415 | 0.101 | | 0.009 | 0.026 | 0.018 | 0.043 | 0.083 | 0.117 | 0.174 | 0.014 |
|
10.0 | 10 | | 0.304 | 0.111 | 0.101 | 0.018 | 0.035 | 0.043 | 0.083 | 0.117 | 0.174 | 0.014 |
10.0 | 32 | 0.417 | 0.101 | | 0.018 | 0.018 | 0.018 | 0.043 | 0.083 | 0.117 | 0.174 | 0.014 |
10.0 | 100 | 0.516 | | 0.008 | 0.026 | | 0.018 | 0.052 | 0.075 | 0.117 | 0.174 | 0.014 |
10.0 | 316 | 0.516 | | 0.026 | 0.009 | 0.009 | 0.018 | 0.043 | 0.075 | 0.117 | 0.174 | 0.014 |
Table VIII
Power and Energy from Particles 600 m from the S 052 Experiment(V0
= 0.2 m/sec)
Radius (μm) | Power (10−6 ergs/sec) | νEnergy(10−7 ergs) in
0.114 sec |
---|
4.4 | 0.31 | 0.35 |
5.1 | 0.49 | 0.56 |
6.6 | 0.94 | 1.07 |
7.3 | 1.13 | 1.29 |
8.0 | 1.28 | 1.46 |