Planet Four Clustering investigations

We want to share a quick update on the depth and details we are investigating to close out the last issues for our analysis pipeline for identifying the fans and blotches from the classifications from the original Planet Four.

We recently realized that it might be a good idea to allow different limits for clustering depending on the general marking size. Intuitively this seems to make sense as one automatically takes a bit more care the smaller an object is to mark.

However, more clustering versatility also means more parameters to set which need to be tested for their efficacy.

Below you can see two plots, one for “fan” markings, the other for “blotch” markings, that show different parameter settings for a clustering run and their effects on the final result.

This planet four image tile with the ID ’17a’ is one of the more problematic ones due to its very large but diffusively defined blotch and the markings are, understandably, all over the place.

17a_fan_scalefalse_radiitrueEach plot title has the values EPS and EPS_LARGE called out. These are the above mentioned distance limits for clustering to happen. Here I leave the EPS value, the one for smaller markings constant over several tests, while I step the one for larger markings, EPS_LARGE, between 50 and 90 in steps of 20.

17a_fan_scalefalse_radiitrueAs one can see the large blotch is “surviving” in all cases (which it wasn’t before we introduced the split-by-size clustering approach), while in the fan case it only survives when the “MS” parameter, the number of minimum markings that a surviving cluster needs to have, is at 5. When requesting 7, it’s just not enough markings to have it survive. But that’s okay, because I’m pretty sure that we will have this survive as a blotch rather than a fan, due to the higher number of markings that voted for that.



About Michael Aye

Space Data Digger

4 responses to “Planet Four Clustering investigations”

  1. Dr Geoff Morley says :

    Can I say that fan” markings, the other for “blotch” markings, that show different parameter settings for a clustering are going to determining whether we can find
    1) H2O ?
    2) Place to land ?
    3) The Make up of the soil ?
    4) Make a mapping of Mars ?
    5) All of these things ?

    • Michael Aye says :

      1) No. This project has nothing to do with looking for H2O. Some of the process might be very slightly affected in their visual appearance due to water ice being present, but that would mostly happen in the north (which we don’t have loaded into the Planet Four project) and would most likely only be visible in a spectroscopic dataset and not in the imagers.
      2) I would more call it a definition of a place where NOT to land, due to all the dust eruption activity. 😉
      3) Not precisely, as that usually requires a combination with spectroscopic data, although we could think about combining it with that data. But we do hope to understand the rough separation of sand-like and dust-like material better from this project.
      4) We will map our results onto a background map, which we will publish, also for public use.

      • Dr Geoff Morley says :

        Thanks for that
        So it will be like what Patrick Moore did on the mapping of the moon but more as a collective

Trackbacks / Pingbacks

  1. Planet Four Progress | Planet Four Blog - April 19, 2017

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: