Sumários
CCD image processing (Part III)
19 Outubro 2021, 09:00 • André Maria da Silva Dias Moitinho de Almeida
- Explanation of the CCDPROC task parameters. Explanation of the different image combination algorithms with outlier rejection.
:: Image processing:- Definition of the geometry of the overscan area and the data area.
- Calculation and correction of the overscan level. Examination of processed images
- Combination of bias images into a master bias. Comparison of the combined image with the individual ones (noise reduction).
:: In-depth examination of outliers and bad pixels rejection algorithms in combining images
- Combinations of 100 bias images. Analysis of the combined super master bias
:: Image processing:
- Application of Zero correction (bias) to images with an exposure time greater than 0.
Telescopes, instruments and astronomical observatories (part II)
19 Outubro 2021, 08:00 • André Maria da Silva Dias Moitinho de Almeida
- Compensate for the effect of turbulence: Adaptive optics (introduction)
- Active optics
- Comparison of primary mirror sizes and the evolution of their size.
Telescopes, instruments and astronomical observatories (or instruments and technologies for astronomical observation)
14 Outubro 2021, 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 the atmosphere in the acquisition of spatial images: Turbulence; absorption; reddening
Further reading: Chap 2 and 3 of McLean (Electronic Imaging in Astronomy)
CCD image processing (Part II)
12 Outubro 2021, 09:00 • André Maria da Silva Dias Moitinho de Almeida
- IRAF software hands-on tutorial (continued)- Inspection of image metadata (content of headers)
- Examination of images of science, bias and flat field with the task imexamine
- Determination of the gain and reading noise of a CCD
CCDs [Part V]
12 Outubro 2021, 08:00 • André Maria da Silva Dias Moitinho de Almeida
:: Instrumental signatures and other effects on CCD images (cont)
- Bias
- Dark current
- Flat fields
- Fringing