The Window Sill Observatory

April 3, 2012

Solar Animation Tutorial

Filed under: Animations, Software, Sun, Tutorials — Dave @ 1:35 pm

This tutorial was produced to show the work flow involved in creating these solar animations.

You can download a zipped folder of solar Fits files to try out from here (190mb). Go direct to step 4 if you download them. Alternatively, you can download the complete set of processed PNGs here (59mb) and go directly to step 5.

Required Software (see links at right)

ASCOM, DFM, DSSR, DVS, AviStack, VirtualDub, RGB filter for VirtualDub (http://emiliano.deepabyss.org/)

1. Setup Telescope Mount and Camera

Open DSSR and click the Telescope button and choose your mount. Check that your field of views suit your camera and scope. My DMK21 on a PST has horizontal FOV = 0.522 degrees and vertical FOV = 0.392 degrees.

Change the drive rate to driveSolar.

Click the Camera button and choose your camera, frame rate and compression. I use 60fps and Y800. Right-click on the camera button to show the camera control dialog, select the UVC Video Controls tab and set Exposure to automatic and Gain to manual. Select the Video Proc Amp tab and set Gamma and Gain to manual.

Adjust your PST tuning and the UVC Gain and Video Gamma sliders to show the prominences and surface features simultaneously. Close the camera properties dialog.

2. Focus

Open DFM and move the focus area over a distinctive feature, preferably including part of the solar edge. Press the Set button. Select VU Both from the dropdown that currently shows Live. Check that image deshifting is turned on. Click Settings and turn on all CPU cores and set the minimum % to 90%.

Slowly focus from near focus to far focus and back again (or vice versa). Slowly adjust focus to give the maximum DFM meter reading which will be less than 100%. Close DFM.

3. Autoguide and Capture

Click on the DSSR capture button and set the length of video clips and pause between to 20s and 20s. If you have plenty of disk space you can set pause to zero.

Click on the DSSR AutoGuide button to display the AutoGuide dialog. Check the swap target box and set the swap time to 300s. Select a prominent feature and left-click on it on the video window. 

DSSR will start guiding on the target feature. If the target moves quickly off screen, check the relevant Flip box.

Click Start on the Video Capture dialog and go to the pub. Click Stop when you have enough videos captured.

4. Stack and Process Videos

Open AviStack and click File>Load Movie and select your video clips.

Check that the following option is selected under the Parameters and Settings window:

Frame Alignment>Alignment type: Surface

Set menu item Settings>Update display to none.

Select all the videos in the main window and click on the Batch Processing button at bottom. Return to pub.

Click the red X when all videos have been completed.

Delete all the PNG images that AVS produced in your video folder.

Click File>Load images (post processing) and select all the Fits files that are in your video folder.

In the Parameters and Settings window, change the Post Processing and Save Processed Image settings to manual and make sure that Post Processing>Wavelets is checked.

Select one of the Fits files and press Process File button at bottom.

Select 4 layers in the wavelets window and adjust the sliders to bring out the best detail. I use 0.20, 51, 0.40, 8, 0.60, 11, 0.80, 24 reading from top down. Click OK.

In the Save Processed Image dialog, select minimum area and 8bit PNG. Click Save then Close then click the red X to remove this file.

Select the remaining Fits files in the main window and click on Batch processing. AVS will now save your PNG frames to disk.

5. Produce Aligned Movie

Open DVS and left-click on the Load button and select your PNG frames.

Maximise your DVS window and change the Alignment>Divisor setting to 3 to align to 1/3rd pixel accuracy.

Move the frame slider to approximately half way and left-click with your mouse pointer on a prominent feature.

Move the slider back and forwards to check that DVS can find this feature on all frames. (figure 1)

Click the Align Frames button and DVS will align your frames.

Click the Crop button and check the Crop frames box. Adjust the crop rectangle to suit by using the numeric up-downs or by click-dragging on the words Top, Bottom, Left or Right. (figure 2)

Click on the Export button and then on Save and select where to save your AVI movie.

6. Colorise Movie

Open your movie in VirtualDub and scrub it back and forward to see the Sun’s rotation.

Select Video>Filters>Add and choose the Red, Green, Blue filter and click on show preview. Adjust the sliders to colorise the Sun. I use 200%, 100% and 50% from top down. Click Ok then Ok.

Select File>Export>Image Sequence and name your files ‘colors’ with 3 digits and type PNG then press OK. Close VirtualDub.

7. Add Overlays

Open DVS and right-click on Load button (all frames are now same size) and select colored frames. Click on Overlays and check the Use overlays box.

Change the Diameter setting for the scale Earth to 6 and click-drag on the word Position to place it in your frame.

Change the text in the text window to ‘Earth to scale’ and click-drag it below the scale disk. (figure 3)

Click on the Export button and then on Save and then on Yes and select where to save your AVI movie.

You can now upload your video to Vimeo.

You can also use DVS to crop out smaller areas of interest or add real images as overlays.

Click on the figures below for full size versions.

Figure 1

Figure 2

Figure 3

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2 Comments

  1. I have had the opportunity to use your software today to animate 7 hours worth of Solar data, this software is excellent! well done.
    Trent

    Comment by Trent McDougall — April 11, 2012 @ 6:36 am

    • Many thanks Trent – will you be uploading your animation to the web? 7 hours should be enough to see the Sun’s rotation if you slide the DVS frame slider back and forward after alignment.
      Dave

      Comment by Dave — April 11, 2012 @ 5:44 pm


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