Author Affiliations
1School of Geospatial Information, Information Engineering University, Zhengzhou 450001, China2Tianjin Jinhang Institute of Technical Physics, Tianjin 300308, Chinashow less
Fig. 1. Typical values of atmospheric background radiation
Fig. 2. Atmospheric transmittivity at different zenith angles
Fig. 3. Detecting number of stars with different optical responding bands
Fig. 4. Proportion of detected stars in different optical responding bands
Fig. 5. Distribution map of stars detected using different optical response bands
Fig. 6. Daytime infrared star observation system
Fig. 7. Daytime infrared image of Polaris
Fig. 8. Daytime infrared image of Sadr
Fig. 9. Comparison of actual star detection ability in different optical wavebands
| Starlist | Filter | ${\lambda _{eff} }/{\text{μm}}$ | Bandwidth
$\Delta \lambda $$/{\text{μm}}$ | $ {F_\lambda } $$/ W \cdot { {\rm{cm} }^{ - 2} } \cdot {\text{μ} {\rm{m} }^{ - 1} }$ | In-band
$/{\rm{W} } \cdot { {\rm{cm} }^{ - 2} }$ | | USNO | R | 0.620 | 0.125 | 2.42E-12 | 3.03E-13 | | I | 0.767 | 0.148 | 1.26E-12 | 1.86E-13 | | 2 MASS | J | 1.235 | 0.162 | 3.129E-13 | 5.082E-14 | | H | 1.662 | 0.251 | 1.133E-13 | 2.843E-14 | | K | 2.159 | 0.262 | 4.283E-14 | 1.122E-14 |
|
Table 1. Parameters of USNO and 2 MASS photometry systems
[20-21] | Band | R | I | J | H | | Bandwidth/μm | 0.6-0.7 | 0.75-0.85 | 1.2-1.3 | 1.6-1.7 | | Transmissivity | 0.82 | 0.90 | 0.96 | 0.97 | | Radiance/
${\rm{W} } \cdot { {\rm{cm} }^{ - 2} } \cdot{ {\rm{sr} }^{ - 1} } \cdot \text{μ}{\rm{m} } {^{ - 1} }$ | 8.68E-04 | 3.34E-04 | 3.69E-05 | 8.01E-06 |
|
Table 2. Mean values of atmospheric parameters in different bands
| Name | Model | Total
pixels
| Depth | Full well | Dark current | Readout
noise
| | QHY990 | CMOS | 1392×1052 | 12 bit A/D | 120 ke | ≤227 e−/pixel
| ≤150 e− | | ZephIR™ | CCD | 640×512 | 14 bit A/D | 110 ke | ≤125 e−/pixel
| ≤75 e− |
|
Table 3. Typical IR sensor parameters
| Pixel size/μm | Focal length/mm | $ \;\rho $ | Band | $ {\tau _0}(\lambda ) $ | $ {I_b} $$/{\rm{W} } \cdot { {\rm{cm} }^{ - 2} }\cdot { {\rm{sr} }^{ - 1} }\cdot \text{μ} {\rm{m} } {^{ - 1} }$ | $ F(\lambda ) $$/ W \cdot { {\rm{cm} }^{ - 2} }\cdot \text{μ} { {\rm{m} }^{ - 1} }$ | | 5 | 100 | 0.25 | R | 0.81 | 8.68E-04 | 2.42E-12 | | 0.25 | I | 0.89 | 3.34E-04 | 1.26E-12 | | 0.25 | J | 0.85 | 3.69E-05 | 3.129E-13 | | 0.25 | H | 0.95 | 8.01E-06 | 1.133E-13 |
|
Table 4. Typical star sensor operating conditions
| Band | R | I | J | H | | Width
$/{\text{μm} }$ | 0.6-0.7 | 0.75-0.85 | 1.2-1.3 | 1.6-1.7 | | Ratio | 1 | 1.01 | 1.16 | 1.04 |
|
Table 5. SNR ratio of 0 magnitude stars in each band (SNRR100)
| Magnitude | 0 | 1 | 2 | 3 | 4 | 5 | 6 | | R band
| 12 | 26 | 98 | 280 | 870 | 2618 | 8385 | | I band
| 18 | 36 | 126 | 439 | 1422 | 4472 | 14730 | | Jband
| 66 | 177 | 688 | 2182 | 6273 | 17894 | 57975 | | Hband
| 171 | 569 | 1825 | 5527 | 19594 | 45210 | 130851 |
|
Table 6. Star statistics in R, I, J, and H bands
| SNR | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | | Band | R | 26 | 49 | 75 | 100 | 130 | 172 | 205 | 230 | 275 | 300 | | I | 27 | 63 | 102 | 155 | 194 | 252 | 315 | 382 | 441 | 495 | | J | 90 | 294 | 564 | 873 | 1172 | 1441 | 1756 | 2047 | 2351 | 2650 | | H | 297 | 828 | 1372 | 1984 | 2620 | 3312 | 3974 | 4652 | 5359 | 6080 |
|
Table 7. Statistics of the number of detected stars in different optical response bands
| Band | SNR of star sensor with R band 0 magnitude star
| | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 | | R | 0.00% | 0.05% | 2.00% | 2.85% | 3.40% | 4.80% | 5.09% | 5.49% | 5.94% | 6.09% | | I | 0.00% | 0.50% | 4.90% | 9.84% | 15.28% | 22.68% | 28.07% | 35.81% | 42.16% | 48.30% | | J | 0.93% | 4.10% | 12.94% | 23.08% | 33.32% | 44.93% | 56.57% | 64.81% | 71.71% | 77.28% | | H | 4.04% | 20.68% | 40.36% | 60.44% | 76.65% | 87.09% | 92.93% | 96.63% | 98.17% | 99.23% |
|
Table 8. Probability of detecting three or more stars using star sensors with different optical response bands
| Name | Item | I | J | H | | Polaris | Magnitude | 1.22 | 0.795 | 0.46 | | SNR | 4.2 | 6.7 | 8.5 | | Sadr | Magnitude | 1.4 | 1.11 | 0.83 | | SNR | 12.1 | 19.3 | 22.4 |
|
Table 9. Star SNR in different optical response bands
