Planetary maps and de-rotation with WinJUPOS
27 August 2010 Comments
WinJUPOS is a free application for processing and analyzing planetary images. It can do many things but I'll describe the most interesting features: map making and removing planet rotation from AVIs and RGB, LRGB images.
Image measurementsStart the program and choose a planet you want to process from the main menu. Then you can start by "describing" each of your images. Every planetary image needs to have a measurement - IMS file made by WinJUPOS. This is needed to make a map, de-rotate an AVI or make de-rotated LRGB, RGB images. Open Recording -> Image measurement: It will bring up the image measurement window. Load your processed image: After that set date and time (UT/GMT !) as well as longitude and latitude of your observation spot. Next go to "Adj." tab: In this tab you can choose the image channel (color or monochrome from one of available filters) and fit the outline to the planet globe. Usually automatic fitting available under F11 key should do the trick. When the outline matches the globe on the image you can save the measurement: Automatic outline doesn't work for Saturn. You have to place it manually - check my Saturn imaging tips on how to do it. Sometimes if the outline doesn't stick to the planet globe correctly the resulting LRGB, RGB images may get misaligned (color edges on ovals, edges etc.) - if you get such result try improving the outlines.
I use Castrator to crop the AVI and center the planet. This is quite effiecient at aligning channels vs each other. In WinJUPOS I try to make an automatic good overlay on blue or green channel image (seems to work best) and then keep it for every other image. If that produces misaligned color images then I play with the outlines for every image.
De-rotation of R/G/B frames - making LRGB/RGB imagesWinJUPOS can make RGB or LRGB images out of monochrome channels. It makes the color image and also de-rotates the planet in channels to identical rotation state. To do so open Tools -> De-rotation of R/G/B frames: Select measurement for each channel and then click Compile Image to make the final image: Here are my R-RGB and RGB images in the standard and WinJUPOS derotated versions. Each channel is a stack from a 5000 AVI recorded in 3 min - 9 min for the whole set. Note the rainbow edges on Jupiter features in the standard versions:
De-rotation of video streams - de-rotating frames in an AVI
This is a new feature - derotating frames in an AVI so that planet rotation won't blur features during stacking. It needs the AVI, a measurement of a processed image (stacked as normal) and time - start and end time of the recording. Apps like FireCapture save "start at" and duration informations in text files associated with the AVI files...Open De-rotation of video streams from Tools:
- Select the AVI file
- Then enter start and end time of the recording (note: for some reason the end time may change sometimes on its own - if it does - put the correct time back again)
- Select image measurement of the stacked image
- Choose "Corrected Video" option
- Start the derotation
Planetary mapsIf you have one or more images take at different time - showing as the planet rotates you can create a map. You need the measurements for each image, then you can open Analysis -> Map computation: Add all your images and use "Set optimum longitude ranges" to optimize map settings: When you do that then make the map with simple "Compile map" click: If you get some lines or uneven surface made from various images then probably some images overlap to much. Try removing some images that show similar part of the planet, optimize the longitudes and generate it again. Thats all.