GREGOR

GFPI Calibration Data on 2015-04-23


Overview of GFPI Level 1.0 and Level 0.0 data.

Prj_Type=FPI_Date=20150423_Time=074123

Dark Frames

Narrow-Band Dark Frames


Average narrow-band dark frame (568 single exposures with an exposure time of 8 ms) taken at 14:30:43 UT. The image was scaled between the 0.1% and 99.9% values of the intensity distribution.

Image Statistics Value
Minimum 72.94
Mean 76.42
Maximum 77.59
Variance 0.28
Standard Deviation 0.53
Mean Absolute Deviation 0.33
Skewness -2.68
Kurtosis 8.34

Broad-Band Dark Frames


Average broad-band dark frame (568 single exposures with an exposure time of 8 ms) taken at 14:30:43 UT. The image was scaled between the 2% and 98% values of the intensity distribution.

Image Statistics Value
Minimum 51.67
Mean 52.76
Maximum 59.91
Variance 0.54
Standard Deviation 0.74
Mean Absolute Deviation 0.40
Skewness 4.45
Kurtosis 25.29

Narrow-Band Dark Frames


Average narrow-band dark frame (568 single exposures with an exposure time of 120 ms) taken at 15:12:57 UT. The image was scaled between the 0.1% and 99.9% values of the intensity distribution.

Image Statistics Value
Minimum 74.98
Mean 79.93
Maximum 98.84
Variance 0.67
Standard Deviation 0.82
Mean Absolute Deviation 0.51
Skewness -1.65
Kurtosis 7.37

Broad-Band Dark Frames


Average broad-band dark frame (568 single exposures with an exposure time of 120 ms) taken at 15:12:57 UT. The image was scaled between the 2% and 98% values of the intensity distribution.

Image Statistics Value
Minimum 55.90
Mean 56.69
Maximum 83.27
Variance 0.62
Standard Deviation 0.79
Mean Absolute Deviation 0.42
Skewness 4.73
Kurtosis 32.35

Flat-Field Frames

Narrow-Band Flat-Field Frames


Average narrow-band flat-field frame (560 single exposures with an exposure time of 8 ms). The image was scaled between the 0.01% and 99.99% values of the intensity distribution.

Image Statistics Value
Minimum 2321.93
Mean 2511.02
Maximum 2585.17
Variance 1465.27
Standard Deviation 38.28
Mean Absolute Deviation 29.36
Skewness -1.34
Kurtosis 2.04

Broad-Band Flat-Field Frames


Average broad-band flat-field frame (560 single exposures with an exposure time of 8 ms). The image was scaled between the 0.01% and 99.99% values of the intensity distribution.

Image Statistics Value
Minimum 2631.34
Mean 2744.05
Maximum 2835.91
Variance 529.22
Standard Deviation 23.00
Mean Absolute Deviation 18.22
Skewness -0.34
Kurtosis -0.05

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 [27.94″, 19.52″]. 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 19:37:34 UT on 2017-11-10.

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.