JCP's Software Page
Image Processing
Grid
Grid Centering
Unprocessed CCD picture showing IO in front of Jupiter
Using ephemerids a synthetic picture of the planet is computed, getting time from file header, taking into account sun illumination, limb darkening, light diffraction and diffusion determined by turbulence, atmosphere and instrument.
That synthetic image is then automaticaly adjusted on the true image, allowing a very precise determination of the true geometric center of the planet.
The grid is then centered on the planet, and computed positions of satellites presented as '+' and their shadows as 'x'
You can observe the near perfect superposition of the cross and IO; typical errors are of the order of 0.2 arcsec. Scale is 0.13" / pixel, exposure is 0.079 s. See Home Page for more information.
The green line limits points used while computing planisphere. Points under satellites and their shadows are automaticaly excluded from planisphere.
For any problem or comment please mail to J-Cl PELLE