Planet Four Talk

The hitchhiker's guide to measurement and scale.

  • JellyMonster by JellyMonster

    Announcement - I have had permission (through a series of questions) to display these Google Map images.

    Warning, warning... please bear in mind, that the aerial photos are cropped off on one side, to fit in the available gap. So instead of being 840 x 648 pixels, they are 803 x 648. I have moved the scale legend over to the top right.

    The Google Map images are to help users visualise what measurements look like from above. This can then be applied to the Mars photos once we know for sure the actual scaling used.

    ↓ 2000 metres across (2 kilometres) - remember part of it has been cropped off (applies to all images)... so less 5% (approx).

    ![1] (https://dl.dropbox.com/s/8641e612b4i2o3p/GoogleMap1b.jpg)

    ↓ 1000 metres across (1 kilometre)

    ![2] (https://dl.dropbox.com/s/cy7m662t2o8lone/GoogleMap2b.jpg)

    ↓ 500 metres across

    ![3] (https://dl.dropbox.com/s/ttku0vzw0fpqpdp/GoogleMap3b.jpg)

    ↓ 250 metres across (approx)

    ![4] (https://dl.dropbox.com/s/4k9zeofwp0fesw7/GoogleMap4b.jpg)

    ↓ 125 metres across (approx)

    ![5] (https://dl.dropbox.com/s/05e726fxpf4ydc6/GoogleMap5b.jpg)

    Posted

  • Kitharode by Kitharode moderator

    Outstanding work from the Wizard of Imagery. Bravo, I say - Encore. Judging from the thin spider fans it's pretty windy in there. 😉

    Definately part of my citizen science toolbox. Many thanks JM.

    I found that Ctrl - (Control + minus key) brought more of the picture into view. My initial 'zoom' position cropped off an additional strip with the scale bar on it and that confused me at first. Might be different on your screen.

    Posted

  • JellyMonster by JellyMonster

    Thank you. I find it quite useful myself.

    Judging from the thin spider fans it's pretty windy in there. 😃

    Yes, I noticed them too 😄

    Posted

  • Kitharode by Kitharode moderator

    Another useful idea from JM for when you're trying to point out a detail in an image, is to 'grid' it. Searching for a tiny spider I couldn't see in an image he said "Divide into nine squares like your alphanumeric keypad. Its in square 9. Bottom right of that, number 9 again". Brilliant. Still can't find it, but now he can tell me how big it is I've half a chance - or 1/9th at least

    Posted