Image #69, basic processing [4.2 kB]
Download this image in fits [72 kB] format.
These images were obtained with a 750 nm Ealing bandpass filter of 40 nm FWHM. Images acquired at UT 14:44-14:45 with 250 ms exposure time at f/45 with the SVST. Detector was a Kodak Megaplus 1.6 10-bit CCD with no cooling. Pixel scale 0.08 arcsecs.
For this daylight observing sequence (Mercury altitude 75 degrees, sun altitude 55 degrees, eastern elongation 20 degrees) 400 images were software-selected and saved in real-time from a total of several thousand acquired, of which 29 were considered sharp enough to process further. Processing sequences of the two most detailed images are shown below.
The first image is after flatfielding (flatfields obtained from data frames). Second image is after fourier filtration with a Wiener filter constructed from frequency information of image #69. Third image is result after further application of unsharp mask with amplification factor of 1.6 and filter size 5x5 pixels.
Hermeographic directions are: N towards the upper left cusp, E towards the limb. Classical features like the bright regions Aurora, Tricrena and Solitudo Hermeae Trismegisti may be identified.
Observations and image processing by J. Warell. Please note that image quality is superior in the fits versions.
Image #69, basic processing [4.2 kB]
Download this image in fits [72 kB] format.
Image #69, Wiener filtering [3.6 kB]
Download this image in fits [75 kB] format.
Image #69, unsharp masking [4.1 kB]
Download this image in fits [75 kB] format.
Image #83, basic processing [3.7 kB]
Download this image in fits [72 kB] format.
Image #83, Wiener filtering [3.9 kB]
Download this image in fits [75 kB] format.
Image #83, unsharp masking [4.2 kB]
Download this image in fits [75 kB] format.
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