A Preview of SAOImage DS9 Registering Images from 12 July 2004 [Slide 1] This PowerPoint presentation is the first designed to introduce Venus Winds Project analysts to SAOImageDS9 astronomical software. The presentation shows examples of DS9’s manipulation of Venus gray-shade images (in standard FITS format) to display contour maps of brightness levels (slides 2 and 3). Slides 4 through 6 show closeups of the contours. Slide 7 displays 13 targets with associated brightness values for local local maxima and minima values. 14 May 2015

Frame 0001 12 July 2004 Gap [Slide 2]—Example of an image of Venus obtained on 12 July 2004, enhanced to show Venus clouds (dark areas) and gaps in the clouds (light areas). Cloud

12 July 2004 Frame 0001 Gap Cloud [Slide 3] Frame 0001 as displayed by DS9, using a rainbow color palette where orange codes for relatively low pixel values (darker areas in the FITS image) and green are relatively high pixel values (brighter areas in the FITS image). Note that orange correlates with clouds and green correlates with gaps in the clouds.

12 July 2004 Frame 3300 Gap Cloud [Slide 4] Frame 3300, captured about two hours later. Note that the target features have barely moved to the west (Frame 0001).

data0001.a.fits [Slide 5] Enlarged view of Slide 3 (Frame 0001). Note how crowded the contours are close to the terminator (blue and solid green area) and the sunlit area (red).

Contour Detail [Slide 6] Closeup of brightness contours where yellowish-green areas are higher brightness levels than the reddish-orange areas.

Tracking Map data0001 Contours 12 July 2004 [Slide 7] A tracking map of bright and dark spots (+n symbol) with associated pixel value. For example +1 1848 means target #1 has a pixel value of 1848, a relatively bright spot (meaning this is a gap) and +9 940? is a much darker spot (meaning this a cloud). Questionable (?) values indicate that the brightness level varies erratically in the eight adjacent pixels.