GREGOR

GFPI Calibration Data on 2017-09-28


Overview of GFPI Level 1.0 and Level 0.0 data.

Prj_Type=GFP_Date=20170928_Time=074731

Dark Frames

Narrow-Band Dark Frames


Average narrow-band dark frame (126 single exposures with an exposure time of 20 ms) taken at 11:30:49 UT. The image was scaled between the 0.1% and 99.9% values of the intensity distribution.

Image Statistics Value
Minimum 52.80
Mean 53.65
Maximum 54.93
Variance 0.04
Standard Deviation 0.20
Mean Absolute Deviation 0.16
Skewness 0.12
Kurtosis 0.41

Broad-Band Dark Frames


Average broad-band dark frame (126 single exposures with an exposure time of 20 ms) taken at 11:30:49 UT. The image was scaled between the 2% and 98% values of the intensity distribution.

Image Statistics Value
Minimum 43.59
Mean 44.45
Maximum 50.06
Variance 0.47
Standard Deviation 0.68
Mean Absolute Deviation 0.35
Skewness 4.41
Kurtosis 23.32

Flat-Field Frames

Narrow-Band Flat-Field Frames


Average narrow-band flat-field frame (120 single exposures with an exposure time of 20 ms). The image was scaled between the 0.01% and 99.99% values of the intensity distribution.

Image Statistics Value
Minimum 1053.71
Mean 1634.44
Maximum 1699.52
Variance 815.26
Standard Deviation 28.55
Mean Absolute Deviation 20.62
Skewness -2.90
Kurtosis 21.39

Broad-Band Flat-Field Frames


Average broad-band flat-field frame (120 single exposures with an exposure time of 20 ms). The image was scaled between the 0.01% and 99.99% values of the intensity distribution.

Image Statistics Value
Minimum 1324.86
Mean 1792.31
Maximum 1971.37
Variance 247.76
Standard Deviation 15.74
Mean Absolute Deviation 10.54
Skewness -2.78
Kurtosis 43.17

Blue-Shift Map

Blue-Shift Map

Fabry-Pérot etalons results in a blue-shift across the field-of-view (FOV).The blue-shift is derived from the focussed flat-field frames. A second-order polynomial is fitted to the blue-shift map to remove artifacts from dust particles and fringes. Misalignment of the optical and mechnical axes of the etalons leads to a displacement of blue-shift map from the center of the FOV. The minimum of the blue-shift map is indicated by a white cross at [33.70″, 15.39″]. The white contour lines placed 1 pm apart clearly show the increase of the blue-shift towards the periphery of the FOV.

Prefilter Curve

Prefilter

The transmission curve of the prefilter is approximated by a Gaussian (blue), which is fitted to a long spectral scan (red) covering a significant part of the GFPI scan range. The highlighted spectral region refers to the scan range of the science data.

GFPI/FTS Spectra

Long spectral scan (red) after division by the transmission curve of the prefilter. The corresponding spectrum (blue) of the Fourier Transform Spectral (FTS) atlas (Neckel, H., Labs, D. 1984: The Solar Radiation between 3300 and 12500 Å. Solar Physics 90, 205–258, ADS) is shown for comparison. The FTS spectrum was convolved with the approximate transmission profile of the dual-etalon FPI.


Overview of GFPI Level 1.0 and Level 0.0 data.

 

Webpage automatically created with sTools (Kuckein et al. 2017) at 13:54:47 UT on 2018-06-19.

The GREGOR solar telescope was built by a German consortium under the leadership of the Kiepenheuer Institute for Solar Physics in Freiburg with the Leibniz Institute for Astrophysics Potsdam, the Institute for Astrophysics Göttingen, and the Max Planck Institute for Solar System Research in Göttingen as partners, and with contributions by the Instituto de Astrofísica de Canarias and the Astronomical Institute of the Academy of Sciences of the Czech Republic.