Sumários

Telescopes, instruments and astronomical observatories - II

16 Outubro 2025, 11:30 • André Maria da Silva Dias Moitinho de Almeida

  • Overcoming the effect of turbulence: Adaptive optics, laser guide stars
  • Reflecting telescopes and variations on their design.
  • Optical off-axis distortions

CCD image processing (Part III)

14 Outubro 2025, 09:00 • André Maria da Silva Dias Moitinho de Almeida

  • Image processing (cont):
    • Combination of bias images into a master bias. 
    • Comparison of the combined image with the individual ones (noise reduction).
    • Application of Zero correction (bias) to images with an exposure time greater than 0 (flatfield and object).

Telescopes, instruments and astronomical observatories (or instruments and technologies for astronomical observation) - I

14 Outubro 2025, 08:00 • André Maria da Silva Dias Moitinho de Almeida

  • What does a telescope do?
  • Collecting area and its effect on light concentration and resolution. Diffraction limit concept.
  • Refracting telescopes.
  • Effects of atmospheric turbulence in the acquisition of images of space.

Further reading: Chap 2 and 3 of McLean (Electronic Imaging in Astronomy)

CMOS detector arrays

9 Outubro 2025, 11:30 • André Maria da Silva Dias Moitinho de Almeida

  • CMOS detector definition
  • CMOS detector principles of operation
  • Performance of modern CMOS detectors
  • Examples of CMOS detectors

CCD image processing (Part II)

7 Outubro 2025, 09:00 • André Maria da Silva Dias Moitinho de Almeida

  • Explanation of the astropy CCDPROC task. 
  • Explanation of different image combination algorithms, including outlier rejection.
  • Image processing:
    • Definition of the geometry of the overscan area and the data area.
    • Calculation and correction of the overscan level. 
    • Trimming the overscan section
    • Examination of processed images