Juno PDS data |
Juno PDS data |
Jan 8 2016, 10:15 PM
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#1
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Administrator Group: Admin Posts: 5172 Joined: 4-August 05 From: Pasadena, CA, USA, Earth Member No.: 454 |
There is now PDS-format JunoCam cruise and Earth flyby data available; it's been submitted to the PDS, but MSSS has gone ahead and posted it on their website. I've created an index page to it here. Unlike my usual index pages, there aren't any thumbnails because of the odd nature of JunoCam images, with their long skinny shapes and interleaved framelets. I haven't played much with these data because it's a bit beyond my skill -- I look forward to seeing what any of you can do with it.
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Jan 22 2016, 05:56 PM
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#2
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Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
This week I worked on a better understanding of the hot pixels, mainly in order to infer a specific point noise filter which protects stars.
The stars will help geometric calibration of the camera, which is an ingredient for accurate RGB registering. Here an excerpt of the observed behavior of the hot pixels: TDI causes hot pixels to show up as "hot streaks" with the number of TDI steps as length in pixels. "Hot streaks" grow downward with increasing TDI, if the CH4 filter is defined as "up" and the red filter as "down". Hot pixels vary over months, mostly in number, but intensity can vary, too. Here an example comparing hot streaks of 2012, doy (day of year) 294, with 2014, doy 038: The 2012294 image has been obtained by stacking all framelets of the six TDI 60 images JNCE_2012294_00R036_V01 to JNCE_2012294_00R041_V01, followed by kind of a horizontal hipass filter. The 2014038 image is the according processing result of the four TDI 80 images JNCE_2014038_00R114_V01 to JNCE_2014038_00R117_V01. I've then defined a heuristics which reduces the images further to estimated hot pixel positions with respect to the considered framelet, lower left corner defined as coordinates (0;0). Hot pixels may be outside the - in this case - red filter readout zone, even in the green filter readout zone, but the streaks reach the red filter readout zone. So, hot pixel positions beyond framelet y-coordinate 127 occur. file_list_red_01.txt_hot_pixels.csv.txt ( 2.02K ) Number of downloads: 1058 file_list_red_03.txt_hot_pixels.csv.txt ( 3.19K ) Number of downloads: 1061 When combining hot pixels of the red and the green filter, streaks starting in green and ending in red can actually be observed. These inter-filter hot streaks confirm the relative y-offset of 155 pixels between the red and the green readout zone. I didn't see good data for the blue filter; thus far, those show strong compression artifacts. Nevertheless, you may see some matches with the green filter. Here an example of stacked and hipass-filtered framelets as insets in a simulation of TDI 80 hot streaks from reduced data: CH4 input data were TDI 64 (of 2011238), therefore the streak length in the simulation is different from the inset image. The CH4 data are early in the cruise. Therefore matchings with the blue data are less likely. |
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