Table 1.
QHY-174M GPS CMOS camera characteristics
| Model | QHY174GPS M |
| Sensor | SONY IMX174 CMOS |
| Pixel Size | 5.86 μm ×5.86 μm |
| Effective Pixel Area | 1920 × 1200 |
| Effective Image Area | 11.25mm×7.03mm |
| QE | 78% |
| AD Sample Depth | 12/10bit (output as 16bit and 8bit) |
| Frame Rate | 138FPS@1936×1216, 260FPS@960×600 |
| Readout Noise | 5.3e-@Gain0% 2.8e-@Gain60% 1.6e-@Gain100% |
| Exposure Time Range | from 5 μs to 900 sec |
| Binning | 1×1,2×2 |
| Anti-Glow Control | Yes (Reduces amplifier glow significantly) |
| Shutter Type | Electric Global Shutter |
| Computer Interface | USB 3.0 Super Speed |
| Cooling System | Dual Stage TEC cooler (-40C below ambient) |
| Time-Stamp Precision | 1 micro-second of the GPS UTC clock |
Figure 1.
QHY-174M GPS CMOS camera (left) and view of the camera with GPS antenna (right)
Table 2.
The goodness of star profile fit with different functions
| Function | Gauss | Lorentz | Moffat |
|---|---|---|---|
| R2 | 0.8623 | 0.9166 | 0.9477 |
Figure 2.
Left: star profile with Moffat 2D function fit (red). Right: Residuals.
Table 3.
Selected standard stars from Landolt catalogue
| Star Name | mV | mR | V-R | SpType | Star Name | mV | mR | V-R | SpType |
|---|---|---|---|---|---|---|---|---|---|
| SA 112 275 | 9.905 | 9.258 | 0.647 | K2D | SA 113 366 | 13.537 | 12.914 | 0.623 | – |
| SA 112 595 | 11.352 | 10.453 | 0.899 | K2:III D | SA 113 177 | 13.560 | 13.104 | 0.456 | – |
| SA 112 223 | 11.424 | 11.151 | 0.273 | F5D | SA 113 195 | 13.692 | 13.274 | 0.418 | – |
| SA 112 704 | 11.452 | 10.630 | 0.822 | – | SA 113 272 | 13.904 | 13.534 | 0.370 | – |
| SA 112 822 | 11.549 | 10.991 | 0.558 | G8:IIID | SA 113 307 | 14.214 | 13.584 | 0.630 | – |
| SA 112 805 | 12.086 | 12.023 | 0.063 | A0D | SA 113 182 | 14.370 | 13.968 | 0.402 | – |
| SA 112 250 | 12.095 | 11.778 | 0.317 | F8D | SA 114 176 | 9.239 | 8.439 | 0.800 | K4/5E |
| SA 113 466 | 10.004 | 9.723 | 0.281 | F5D | SA 114 670 | 11.101 | 10.456 | 0.645 | K1.5:IIID |
| SA 113 475 | 10.306 | 9.736 | 0.570 | G5D | SA 114 548 | 11.601 | 10.863 | 0.738 | K2D |
| SA 113 342 | 10.878 | 10.341 | 0.537 | – | SA 114 654 | 11.833 | 11.465 | 0.368 | G0D |
| SA 113 156 | 11.224 | 10.921 | 0.303 | – | SA 114 750 | 11.916 | 11.889 | 0.027 | B9D |
| SA 113 259 | 11.742 | 11.121 | 0.621 | K0:III D | SA 114 446 | 12.064 | 11.667 | 0.397 | – |
| SA 113 493 | 11.767 | 11.337 | 0.430 | G5D | SA 114 656 | 12.644 | 12.097 | 0.547 | K1:IIID |
| SA 113 440 | 11.796 | 11.433 | 0.363 | – | SA 115 271 | 9.695 | 9.342 | 0.353 | F8D |
| SA 113 459 | 12.125 | 11.818 | 0.307 | – | SA 115 516 | 10.434 | 9.871 | 0.563 | G8IVD |
| SA 113 492 | 12.174 | 11.832 | 0.342 | G0E | SA 115 420 | 11.161 | 10.875 | 0.286 | F5D |
| SA 113 339 | 12.250 | 11.910 | 0.340 | F8D | SA 115 554 | 11.812 | 11.226 | 0.586 | K1.5:IIIC |
| SA 113 191 | 12.337 | 11.866 | 0.471 | – | SA 115 412 | 12.209 | 11.882 | 0.327 | – |
| SA 113 495 | 12.437 | 11.925 | 0.512 | G:D | SA 115 268 | 12.494 | 12.128 | 0.366 | – |
| SA 113 158 | 13.116 | 12.709 | 0.407 | – |
Figure 3.
Example of FITS files to process. Object is in the centre of the frame and its shape is point, the stars have trail shape.
Figure 4.
Logical diagram of the satellite photometry script
Figure 5.
Part of LC of Topex/Poseidon artificial satellite (NORAD 22076) observed at Derenivka station on Aug 06 2020 in R filter. Time of exposition 0.2 sec. Photometry errors are 0.006 ÷ 0.040 mag.
Figure 6.
Top: Observations of satellite COSMOS 2502 (NORAD 40358) from two observational sites - Uzhhoorod in B,V filters with use of photo-multiplier (blue and green lines), Derenivka in R filter with QHY174M-GPS camera (red line).
Observation made on Nov 09 2020. Bottom: Colour indexes B-V, V-R and B-R