Juno at Jupiter, mission events as they unfold |
Juno at Jupiter, mission events as they unfold |
Jul 5 2016, 07:53 PM
Post
#1
|
|
Merciless Robot Group: Admin Posts: 8784 Joined: 8-December 05 From: Los Angeles Member No.: 602 |
This topic will consist of discussion of Juno operations post-JOI until end of mission, currently anticipated in Feb 2018.
-------------------- A few will take this knowledge and use this power of a dream realized as a force for change, an impetus for further discovery to make less ancient dreams real.
|
|
|
Aug 5 2016, 11:47 AM
Post
#2
|
|||||||||
Senior Member Group: Members Posts: 2346 Joined: 7-December 12 Member No.: 6780 |
Quantitative measurements of the structure and velocity of Jupiter's cloud top may require a very accurate calibration of JunoCam's geometry.
However, when going well below one raw pixel alignment accuracy, it's hard to measure inaccuracies visually. Here seven animated examples, one for each of seven considered camera parameters, with five frames for each of the animated gifs. You may try to find out in which of the gifs you can perceive a change of color at the limbs, before looking at the graphics below. Varying the assumption of JunoCam frames per Juno rotation: Varying the x/z ratio of the pinhole part of the model: Varying the x-position of the optical axis: Varying the y-position of the optical axis: Varying the Brownian radial distortion coefficient K1: Varying the Brownian radial distortion coefficient K2: Varying the assumption of the JunoCam CCD being rotated around its optical axis: The subtle changes of the RGB misalignment can be quantfied more accurately by comparing the positions of the centroids for each color band in the processed images: The misalignment unit in the graphics and data is 30 arc seconds, or about 1/4 raw pixel. Here the values as csv file: JNCE_2016164_00C196_V01_proc013.BMP_RGBGradCSV.txt ( 10.09K ) Number of downloads: 232 The graphics suggests locally linear dependence of the misalignments on the considered parameters. The misalignment can hence be approximated well by a system of linear equations, eventually written as y=Ax+b, with x,y,b vectors, and A a matrix. Since the number of parameters is 7, but there are only 4 linearly independent measurements, the space of solutions with (close to) perfect alignment is likely to be 3-dimensional for each image. The set of solution spaces for a sequence of images can then undergo statistical analysis. The graphics also suggests, that the x-alignment of the blue channel (yellow lines) can reasonably be obtained only by adjusting the y-position of the optical axis and/or adjusting the rotation of the camera around the optical axis, unless additional parameters are added to the model. |
||||||||
|
|||||||||
Lo-Fi Version | Time is now: 25th June 2024 - 04:58 AM |
RULES AND GUIDELINES Please read the Forum Rules and Guidelines before posting. IMAGE COPYRIGHT |
OPINIONS AND MODERATION Opinions expressed on UnmannedSpaceflight.com are those of the individual posters and do not necessarily reflect the opinions of UnmannedSpaceflight.com or The Planetary Society. The all-volunteer UnmannedSpaceflight.com moderation team is wholly independent of The Planetary Society. The Planetary Society has no influence over decisions made by the UnmannedSpaceflight.com moderators. |
SUPPORT THE FORUM Unmannedspaceflight.com is funded by the Planetary Society. Please consider supporting our work and many other projects by donating to the Society or becoming a member. |