View Full Version : Introducing A.S.T.R.O. - a search methodology

2012-Jun-29, 03:23 AM
Introducing A.S.T.R.O. - a search methodology for consistently and reliably marking KBO candidates in a citizen scientist, crowd-sourcing forum.


A nalyze

What is the quality of the on-screen image? Does the image display sufficient clarity and detail to allow you to distinguish the messy star residuals from the transients? Is the projected image one with which you can reliably mark transients?

Check a number of the large white blobs to determine if they repeatedly display appended/adjacent/splintered white blobs that try to mimic actual transients. If you note that most of the large blobs bear appended smaller blobs, then that appearance is due to image artifacts.

If you judge the image clarity and detail to be insufficient, mark the image as “Bad Image” and move on to the next image. Guessing at suggestive transients in a bad image does not help this project.

S earch

Develop a search pattern that permits you to eyeball the entire screen. Don’t just hope that something will jump out and capture your eye. Move your eyes deliberately across the screen in a systematic manner to seek out the transients for marking. Consistently move your eyes in that same pattern over and over again so that it becomes second nature to you. This allows you to develop confidence that you have consistently and reliably searched each screen in a diligent and comprehensive manner.

Enlarge or reduce your screen image to dimensions with which you are comfortable. Test different screen sizes to discover your own personal preference for transient searching.

T ransient recognition

Do blobs in the image match the description provided in the Tutorial? If so, then mark the transient as guided by the Mapping Tools. Look for the solid white blobs. Transients worth marking usually display smooth (not irregular) edges. Transients that are actually artifacts often are recognized by their appended/attached/splintered smaller white blobs.

The transients upon which I place 'high value' normally stand alone against the gray/dark background. They normally don't append themselves to other white blobs or white residuals and their edges don't touch upon extraneous dark blobs or dark residuals.

The 'tool' I use to distinguish transients from asteroids is as follows - I draw an imaginary vertical line down the center of the circular or elongated white blob. If both the left and right halves depict equal brightness and 'sharpness' to their respective edges, then I mark that blob as a transient. If the imaginary line down the center of the blob divides the blob into regions of unequal brightness or 'sharpness', then I mark that blob as an asteroid.

Star residuals appear as displaying ‘diffused’ edges containing specks and/or regions of grey or dark-colored inclusions. The star residuals are normally elongated in a vertical manner, whereas the transients appear as slightly elongated solid white blobs in a horizontal/diagonal manner.

R econsider

After you are done marking the transients, and before you click the “Done Working” button, reconsider the transients that you have marked. Are there faint transients that you have over-looked during your initial search of the screen image? Are your marked transients consistent with others you have previously marked? Does a second look help you to decide if the transient should be marked as an asteroid or as a KBO candidate instead?

Go to the Gallery for further insights by viewing what other Ice Investigators had marked in the same images that you have viewed. Do you agree with what others have marked? Does seeing what others have marked help you in choosing what transients to mark?

O ptimize

The images are not all consistent in quality. Some images are darker or lighter or even more contrasted than others. There are tricks to improving image quality from your computer.

Under the ‘Done Working’ button there is a link to ‘open image in another window’. Clicking on that line projects the image without the clutter of the frames on the Ice Investigators window. This allows you to focus upon the image and its features.

The ‘Toggle Contrast’ button (when active) does just that. You can view the image at a different darkness/contrast with the click of a single button.

Your monitor should allow you to adjust the brightness, contrast and gamma settings. Experiment with these settings and determine which settings allow you to optimize your ‘seeing’ of the screen images.
Your internet browser should have shortcuts that you can apply to enlarge the screen image. In Internet Explorer this shortcut is ‘CTL +’.

That is A.S.T.R.O.! Repeatedly applying this search methodology will hopefully guide you in confidently and consistently marking transients that allows you to contribute meaningfully to this important Ice Investigators project.

2012-Jun-29, 03:46 PM
Hi Huntrr,

Can I use that as a guest blog post/part of the tutorial so it reaches more folks?

2012-Jun-29, 07:40 PM
Hi Huntrrr, Thank you for ASTRO! I didn't think the contrast thingy was working yet. I have to say that many of the images I have seen really have been a challenge!! Perhaps I thought I was being kind to the team by not marking them as bad! What do you make of the clear blobs with a second touching pale blob?

2012-Jun-29, 10:03 PM
dosey asks: What do you make of the clear blobs with a second touching pale blob?

I've seen blobs of that description several times. It's why I recommend an Analysis of the screen image first. If you recognize repeated instances of main and appended second blobs across the screen, then their appearance is due to an artifact being created during the subtraction process.

Normally, l've noticed the appended clear blobs as a horizontal streak below the main blob (pretending to be an asteroid). Other times, the appended blob appears as a clear white blob at a quadrant to the main blob. Keep looking for those instances, and you should become familiar with them as an image artifact.

Hopefully this will provide some guidance.

2012-Jun-29, 10:15 PM

Kindly share and suggest improvements for the ASTRO methodology.


2012-Jun-30, 05:23 AM
Hi Huntrrr, thanks for sharing your search tips! That's really helpful. :)