(Click for full-size)
During the past few weeks, I have repeated the steps required to process images from the 7/13/04 observations and created additional vector fields of the cloud motion. I have attempted to use different images than before, and to redo the processing, alignment, and compositing completely from scratch to see what effect this may have on the resulting vector fields.
time.txt : universal time of observation of each image,
1041 16:17:01.523765 977.02539608 1042 16:17:03.969390 977.06615650 1043 16:17:06.517683 977.10862805 1044 16:17:08.984247 977.14973745 1045 16:17:11.548302 977.19247170 etc...
coords.txt : center, radius, and error of circle fitted to bright limb of each image,
1041 316.51 220.44 167.81 0.24008 1042 317.38 220.55 167.34 1.36973 1043 317.21 220.64 167.61 0.270484 1044 317.15 221.30 167.03 0.262651 1045 317.79 221.41 167.20 0.255174 etc...
sharpness11.txt : estimated sharpness of each image,
1041 0.0275021 1042 0.0274982 1043 0.0272446 1044 0.0272411 1045 0.0277015 etc...
and bad.txt : list of unusable images,
1107 1110 1111 1112 1113 etc...
were merged into a single file called image_data.txt : information required for subsequent
processing and alignment.
1041 16:17:01.523765 0.00000000 -61.51 -34.56 999.00 999.00 0.0275021000 1042 16:17:03.969390 0.04076042 -62.38 -34.45 999.00 999.00 0.0274982000 1043 16:17:06.517683 0.08323197 -62.21 -34.36 999.00 999.00 0.0272446000 1044 16:17:08.984247 0.12434137 -62.15 -33.70 999.00 999.00 0.0272411000 1045 16:17:11.548302 0.16707562 -62.79 -33.59 999.00 999.00 0.0277015000 etc...
In this new file, the first column is the image number, the second column is the UT, the third column is the UT converted to a decimal minute elapsed from the time of the first image, the fourth and fifth columns are the fitted bright limb coordinates converted to a shift required to center the inverted image, the sixth and seventh columns are the actual shifts required to center the flipped image as determined by FITSRegister, when available, or the value 999 otherwise, and the eighth column is the estimated sharpness.
Out of 2400 total images, the image_data.txt file contains entries for 2220. Many images were rejected automatically from their limb coordinates, either because the image was out of the frame, or because the coadds were not aligned (i.e. the telescope was moving). Some additional images were rejected because while the bright limb coordinates indicated the planet was in the frame, the dark limb was actually partly out of the frame.
sharpness shift method - before brgm sharpness2 shift method - after brgm - r=100 sharpness3 shift method - r=75 * sharpness4 stddevs of disks * sharpness5 stddevs of more disks sharpness6 unsharp mask sharpness7 contrast sharpness8 entropy * sharpness9 fft energy - 17-32 Hz sharpness10 fft energy - 33-64 Hz * sharpness11 fft energy - 9-16 Hz sharpness12 fft energy - 5-8 Hz
(Click for full-size)
(Click for full-size)
For a previous analysis, it was decided to select a few groups of nearby sharp images from obvious peaks in the sharpness plot, even though these sets did not come at evenly spaced time intervals.
(Click for full-size)
(Click for full-size)
For the current analysis, it was decided to divide the observation into 20 minute intervals, and to automatically select the 10 sharpest images from the central 5 minute period of each interval. In this way the resulting composite images would be at regular time intervals, and would, with the exception of the last interval, be at about the same level of sharpness.
(Click for full-size)
The 70 images chosen were:
Interval 1: 1230 1231 1232 1227 1228 1229 1233 1221 1235 1225 Interval 2: 1763 1757 1759 1785 1789 1750 1756 1748 1765 1760 Interval 3: 2124 2123 2113 2140 2118 2121 2117 2112 2139 2116 Interval 4: 2492 2517 2519 2507 2525 2555 2518 2484 2493 2515 Interval 5: 2897 2896 2893 2869 2898 2887 2843 2892 2895 2868 Interval 6: 3205 3160 3212 3161 3204 3162 3206 3215 3159 3182 Interval 7: 3465 3470 3482 3481 3480 3466 3467 3478 3483 3471
Several of the images originally chosen for interval 1 had to be manually rejected because the edge of the dark limb was out of the frame. They were replaced by the next sharpest image in the list for that time interval.