OP Lunch Talk #13

Matt Brealey @matt (mattbrealey.com) talks about the inner workings of AreoBrowser (https://areobrowser.com/), his web-app for viewing Martian terrain models.

Should we have any questions for the speaker, or anybody within the planetary science community who might be able to answer you, please ask below; or share any useful resources related to the topic.

@matt Just saw the talk - thanks. As you start thinking about implementing global extents, I wonder what your thoughts are on viewers like Cesium? As used in several planetary viewers.

And thinking about loading all that data into global layers reminds me about the HiRISE technology test we did last year which loaded all (~500) HiRISE DTMs and their matched HiRISE images (full-res) into Tiled WMS services (hosted on AWS). The test was really for loading all HiRISE 50,000+ RDR images and the Murray-Lab CTX mosaic, but we also hosted a layer for the better controlled HiRISE DTMs and their orthos.

Anyway, I wonder if it is something AeroBrowser could utilize also? It sounds like you are converting the scaled “RGB” elevation maps to a mesh in the browser. If so, I think you might be able to do the same with these Tiled WMSs? Essentially doing the same and taking the DTM pixel values from the Tiled service and creating the same mesh.

This type of layer (e.g. Tiled WMS with built-in resolutions or levels) is used in applications like OpenSpace, the Treks, and I assume QuickMap. And speaking about the lunar version for QuickMap, check out all the LROC DTMs available for AeroBrowser from the LROC Team!

BTW, the Tiled WMS access points (addresses) are available in the zip file found here. For testing you should be able to drop them into QGIS or view the orthos in this simple web viewer. In QGIS, on the DEM/DTM layers you can set the symbology to “hillshade” with an exaggeration of ~0.00005 (which scales Z value in meters to something more reasonable as X/Y axes are in degrees). BTW, a HRSC/MOLA hybrid merged DEM is also available. Note all DTMs were limited to a 16bit range. Although we could use a 32bit bit range within these services, that would limit the number of applications which could make use of it.

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Hey Trent! Sorry for the somewhat massive delay in getting back to you - Nicolas just pointed me this way (thanks Nicolas!) Really glad you liked the talk - audio issues and all :slight_smile:

To be honest, although I know that it’s incredibly capable, I don’t have much experience with Cesium. I’ll dig a little deeper into it.

And your HiRISE tech test sounds SUPER awesome - I’d love to see it if you have anything at all you can share!

I definitely do think I’d be able to utilise the Tiled WMS files - in fact tile loading is one of the next big things on my list for v3! Thank you SO much for the zip file + viewing instructions - I’ll take a look once my current freelance deadlines are out of the way.

The HiRISE/HRSC RGB files I’m currently converting in browser down-scale the original 16bit DTMs to 8bit, so that limitation shouldn’t be a problem. I’m actually kind of embracing the idea that AreoBrowser never needs to really display things at absolute full quality - it should get to a certain useful level and then direct you to the source if you really need the detail that 32bit provides!

My goal is really to make a scientifically useful tool, and whilst I have the dev knowledge, knowing what exactly counts as ‘scientifically useful’ is always a challenge! I’d really love to chat a little more with you about my plans for v3 if you’d be willing to answer a few potentially simple questions at some point :slight_smile:

Thanks again!