Asteroid Zoo Talk

Journey of a Frame Set...

  • jgulvas by jgulvas

    So, once the photographs are taken and strung into a set of frames, what happens to this frame set next? And especially, what happens to a set in which lurks within the confines of its borders an asteroid? I imagine a flowchart; what would it look like?

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  • Dr.Asteroid by Dr.Asteroid scientist, admin

    Are you asking about the Catalina asteroid-finding pipeline? Or about AsteroidZoo?

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  • jgulvas by jgulvas

    Thanks for returning my post. I am wondering what the frame sets that we see have been through, from the moment they are produced until they are cycled through as AsteroidZoo frames being scrutinized by the volunteers. What is the "Catalina asteroid-finding pipeline"? Is it different than the process I am asking about?

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  • Dr.Asteroid by Dr.Asteroid scientist, admin

    Hmm... Let me try and answer the question that you have:

    The images you're looking at are from the Catalina Sky Survey. They took the images (mostly in 2012 to present) and looked for all the asteroids they could find in the data. So, many of the asteroids are known.

    However - we do know that the Catalina data analysis pipeline isn't perfect - the best guess (by Catalina) is that they miss 10% of all the asteroids in an image. That gives a VERY large number of possible targets that were missed. And we (the people behind asteroidzoo) believe that humans have a good shot at being better at certain kinds of missed asteroids - and vastly better at ignoring the random noise in the images.

    The Catalina pipeline (in very short - I don't have access to the actual code, but I've had it described to me) works like this.
    First, find all the sources in each of the four frames.
    Remove all the sources that are present in the same places in each frame.
    From there try and connect the dots for things that move - they need to appear in 3 of the 4 frames and travel in more or less a straight line shorter than 50 pixels. (so if it was a very close asteroid and moved 51 pixels, it would be ignored)
    Those finds that met those requirements would be sent to the operator to examine for validity (checking for obvious problems - the Catalina pipeline often finds many asteroids around star bleeds for example - that are all false detections).

    Does that help?

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