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Show HN: Open-source high-res Mars map, in natural colors

mars26.com

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Re: Show HN: Open-source high-res Mars map, in natural colors

#41

Post by OmicronCeti »

MayeulC wrote: post #33

there seems to be excessive distorsion at the poles. Is this for a lack of data, or is it due to the coordinate system? The poles are the most interesting part to me, but there doesn't seem to be a way to control lighting, so they are at least partially obscured. Moreover, I'd have expected the terminator to be less fuzzy due to Mars' thin atmosphere, but it might be just me.

The coordinate system changes from equirectangular to polar stereo. The poles just don't get good imagery from the MRO. I work extensively with HiRISE data which is collected from the same orbiter as the CTX data this map uses.

Re: Show HN: Open-source high-res Mars map, in natural colors

#42

Post by skybrian »

space2026 wrote: post #13
skybrian wrote: post #10

Very neat, but there are only a few places on Mars I recognize well enough to find. It would be good to have a list of points of interest and a way to go to them. There's also a Twitter symbol at one point on the globe; not sure why?

Nice idea! We'll add a feature layer with points of interest. Clicking the Twitter symbol should show you somebody's tweet on that position. Works in Chrome, and we'll add support for Firefox (soon) which currently blocks it

It would be good to add a way to toggle that layer too.

Re: Show HN: Open-source high-res Mars map, in natural colors

#43

Post by zokier »

I want to like it but its pretty rough as-is. I feel the colors need lot of tweaking to look right, the blending in between missing data on both ctx and viking needs to be improved. Right now the pretty red planet looks sickly and moldy, with awkward artifacts all over the place.

Compare e.g. the surroundings of Jezero crater (Percys landing site) on this Mars26 vs HRSC data:

https://mars26.com/#heading=0&latitude=18.628109809050898&lo...

https://maps.planet.fu-berlin.de/#map=8/4646647.81/1124272.2

Or this region; I'm pretty sure its not supposed to be blue: https://mars26.com/#heading=359.79651286245115&latitude=-40....

Re: Show HN: Open-source high-res Mars map, in natural colors

#44

Post by space2026 »

zokier wrote: post #43

I want to like it but its pretty rough as-is. I feel the colors need lot of tweaking to look right, the blending in between missing data on both ctx and viking needs to be improved. Right now the pretty red planet looks sickly and moldy, with awkward artifacts all over the place. Compare e.g. the surroundings of Jezero crater (Percys landing site) on this Mars26 vs HRSC data: https://mars26.com/#heading=0&latitude=18…

Thanks for the feedback! Yes, it is hard to get right. That's why neither NASA nor Google have a great blend.

The artifacts should be mostly gone with our next version which we are rendering in the next few days.

Greyish areas come from areas where Viking imagery is mostly black. We also updated this part in the next model. Thouhg, that's a tough one.

Let's see how you like the next version!

Re: Show HN: Open-source high-res Mars map, in natural colors

#46

Post by space2026 »

OmicronCeti wrote: post #40
billfruit wrote: post #37

Earlier quoted context omitted.

What is the fundamental dataset used for it? In recent years more probes have done Mars imaging, which probe has given the highest resolution images?

They primarily use CTX, but HiRISE has the highest resolution, 0.25-0.5m/pixel.

Right. HiRISE is awesome, but covers only roughly 5% of Mars surface. Check the blog we posted above [1], it gives very detailed explanation on that.

[1] https://medium.com/mars26/the-most-detailed-mars-map-yet-717...

Re: Show HN: Open-source high-res Mars map, in natural colors

#47

Post by zokier »

space2026 wrote: post #44
zokier wrote: post #43

I want to like it but its pretty rough as-is. I feel the colors need lot of tweaking to look right, the blending in between missing data on both ctx and viking needs to be improved. Right now the pretty red planet looks sickly and moldy, with awkward artifacts all over the place. Compare e.g. the surroundings of Jezero crater (Percys landing site) on this Mars26 vs HRSC data: https://mars26.com/#heading=0&latitude=18…

Thanks for the feedback! Yes, it is hard to get right. That's why neither NASA nor Google have a great blend. The artifacts should be mostly gone with our next version which we are rendering in the next few days. Greyish areas come from areas where Viking imagery is mostly black. We also updated this part in the next model. Thouhg, that's a tough one. Let's see how you like the next version!

Are you also adjusting the overall color? Your images have now strong pinkish cast instead of the more natural orangeish tones.

For parts where viking data is not usable, maybe filling in the color information based upon surrounding area would make at least prettier end result.

Re: Show HN: Open-source high-res Mars map, in natural colors

#48

Post by space2026 »

zokier wrote: post #47
space2026 wrote: post #44

Earlier quoted context omitted.

Thanks for the feedback! Yes, it is hard to get right. That's why neither NASA nor Google have a great blend. The artifacts should be mostly gone with our next version which we are rendering in the next few days. Greyish areas come from areas where Viking imagery is mostly black. We also updated this part in the next model. Thouhg, that's a tough one. Let's see how you like the next version!

Are you also adjusting the overall color? Your images have now strong pinkish cast instead of the more natural orangeish tones. For parts where viking data is not usable, maybe filling in the color information based upon surrounding area would make at least prettier end result.

Yes, those are two really good points. What we do is first we have to find a middle ground on color, contrast, brightness between all Viking photographs. Because there are differences between each. Then we make a decision of what an average color looks like.

Filling in an average color for the overexposed areas is what we'll do for version 1.0 coming in a few days. Running locally it does already look quite nice. Hope it will turn out well on the web app!

Re: Show HN: Open-source high-res Mars map, in natural colors

#49

Post by space2026 »

skybrian wrote: post #42
space2026 wrote: post #13

Earlier quoted context omitted.

Nice idea! We'll add a feature layer with points of interest. Clicking the Twitter symbol should show you somebody's tweet on that position. Works in Chrome, and we'll add support for Firefox (soon) which currently blocks it

It would be good to add a way to toggle that layer too.

Yea, that should be rather straight forward with the Esri API. We should be able to find some time to add it by next week.
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