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A 5.7 Terapixel Mosaic of the Surface of Mars

murray-lab.caltech.edu

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Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#51

Post by prpl »

eutectic wrote: post #16
TomasD wrote: post #13

Earlier quoted context omitted.

You can fly your satellites lower in mars due to atmosphere density, as low as 20km it appears

And presumably the atmospheric distortion is much less as well.

Atmospheric distortion looking down is not as severe as it is looking up. This is because the distortion subtends much greater angles looking up than looking down, since the distortion is close to the observer. Looking down, it’s also true that, at least in daytime, exposures are very short as well by virtue of the earth being very bright.

Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#52

Post by zokier »

tejohnso wrote: post #27
YetAnotherNick wrote: post #20

Earlier quoted context omitted.

WorldView-3 claims to be 31cm resolution: https://worldview3.digitalglobe.com/

Not public. I don't even see a pricing page, so can assume very pricey.

Afaik in the ballpark of $500/25km² for archive images.

Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#53

Post by swiftcoder »

Sharlin wrote: post #48
dylan604 wrote: post #38

Earlier quoted context omitted.

If I wanted to make a textured globe, you just made my oceans totally smooth. Some of the tallest mountain ranges we have are in the area you just nulled out.

And how exactly would satellite imagery (no matter which wavelength range) help you texture the ocean floor in your globe?

Turns out the surface of the ocean has ridges and valleys that match the seafloor, and these can be measured by radar from a satelite

Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#54

Post by zokier »

qwertox wrote: post #31
tejohnso wrote: post #27

Earlier quoted context omitted.

Not public. I don't even see a pricing page, so can assume very pricey.

Also this is appears to be the optical resolution, unrelated to an elevation model.

All major imagining satellites provide stereo imaging suitable for 3d reconstruction. Airbus has whole suite of products around this, and probably the biggest reason why there isn't off-the-shelf products for WV3 is because its just so new.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7248834/

https://www.intelligence-airbusds.com/imagery/reference-laye...

Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#57

Post by aannex »

q87b wrote: post #11

It's quite amazing and simultaneously ridiculous that we have a public 3D model of a distant planet at 5 meters resolution while the best available free and public models of Earth are at 30 meters.

We actually don't have a 5 meter global elevation for Mars. The imagery is 5 mpp but the elevation data used in the links is MOLA and is closer to 500 meters per pixel (with another merged product at 200 mpp). It is almost more weird/cool that we have hundreds (thousands?) of 1 mpp elevation models for small areas of Mars from HiRISE (available for free from the PDS) and larger swaths at ~20 meters per pixel from CTX imagery used in this global mosaic, but still not close to a global product.

various sources: 1. https://astrogeology.usgs.gov/search/details/Mars/GlobalSurv... 2. https://astrogeology.usgs.gov/search/map/Mars/Topography/HRS... 3. https://www.uahirise.org/dtm/ 4. https://stac.astrogeology.usgs.gov/docs/data/mars/ctxdtms/

Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#58

Post by hammock »

>5.0 m/px

How does that compare to , e.g. aerial photography resolution or some familiar standard ?

Edit: ChatGPT gave me:

  .28 cm/px for a studio portrait photo (factor 2000x)
  8.3 cm/px for a landscape photo (factor 60x)
  30-200 cm/px for aerial photos (factor 2-20x)

Re: A 5.7 Terapixel Mosaic of the Surface of Mars

#59

Post by zokier »

hammock wrote: post #58

>5.0 m/px How does that compare to , e.g. aerial photography resolution or some familiar standard ? Edit: ChatGPT gave me: .28 cm/px for a studio portrait photo (factor 2000x) 8.3 cm/px for a landscape photo (factor 60x) 30-200 cm/px for aerial photos (factor 2-20x)

Commercial satellites imaging Earth can do about 30cm/px (or .3m/px), conventional aerial photos are afaik in the ballpark of 5cm/px, drones can do The special thing about this Murray mosaic is that it seamless continuous image across the whole Mars surface, they spent lot of time gluing and stitching the raw images together. Furthermore, important for science, each pixel can afaik be traced back to specific capture, so there is provenance.
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