Sea ice and beer

A while ago I mentioned that I would write something about sea ice. The context was a talk I gave at the 2017 Pint of Science festival in Canberra. It was really quite fun, despite being totally terrified and full of the ‘what ifs’… ten minutes before stepping in. Thanks to some great tips from a Canberra Innovation Network science communication workshop I managed to get it done.

Anyway, The aim of that talk was to give a brief sea ice overview and then show what it’s like as a scientist working in the field – how we think, how we try to solve problems and potential new techniques we see which can help.

The audience was quite impressive – they grasped the material with two hands and had insightful, interesting questions. It was heartwarming.

…but none of that is about sea ice at all. That was all about a talk! So go and read it yourself here and learn more: https://adamsteer.github.io/talks/pintofscience2017/#/ – it uses Reveal.js – so you can use your arrow keys to move around it either linearly (down, then right, then down) or go around how you please. Press ‘s’ to see speaker notes, I’ll finish those in the next week while I’m travelling to FOSS4G.

Most importantly, it explains the sea ice/beer cycle. This is really an under-studied earth system component and needs massive grant funding and more fieldwork. I mean it! Seriously! Without detailed knowledge of sea ice thickness gained by combining many instruments and rigorous field surveys, we will always be nervous that our beer is at risk.

You can also see a deeper dive ( a PhD thesis in 20 or so slides) here – also in Reveal.js: adamsteer.github.io/talks/phd.wrapup .

I hope those slide decks are digestible and leave you with something you didn’t know before – the sea ice/beer cycle for one; but also how sea ice gets measured and just a few of the issues surrounding how to make a realistic assessment about how much sea ice exists on the southern ocean. It’s super-complex! It’s also about the most mind blowing place I’ve ever been – we don’t need to go to Mars.. the pack ice zone is much closer and still a totally foreign world.

What a planet we live on…

You can call me Doctor now.

Glorious bearded philosopher-king is clearly more appropriate, but Doctor will do.

After six years of chasing a crazy goal and burrowing down far too many rabbit holes in search of answers to engineering problems, I got a letter from the Dean of graduate research back in late October. My PhD is done!

So what exactly did I do? The ten minute recap is this:

1. I assessed the utility of a class of empirical models for estimating snow depth on sea ice using altimetry (snow height). The models were derived from as many in situ (as in holes drilled in the ice) measurements as I could find, and I discovered that they are great in a broad sense (say hundreds of metres), but don’t quite get the picture right at high resolutions (as in metres). This is expected, and suspected – but nobody actually did the work to say how. So this was published (and of course, is imperfect – there is much more to say on the matter).

2. For a LiDAR altimetry platform I spent a lot of time tracking down noise sources, and ended up implementing a method to estimate the 3D uncertainty of every single point. This was hard! I also got quite good at staring at GPS post-processing output, and became quite insanely jealous anytime anyone showed me results from fixed-wing aircraft.

3. Now having in hand some ideas about estimating snow depth and uncertainties, I used another empirical model to estimate sea ice thickness using snow depths estimated from sea ice elevation (see 1), and propagating uncertainty from LiDAR points through to get an idea of uncertainty in my thickness estimates (see 2). Because of spatial magic I did with a robotic total station on SIPEX-II (see the blog title pic – that’s me with my friendly Leica Viva), I could also coregister some under-ice observations of sea ice draft and use them to come up with parameters to use in the sea-ice thickness from altimetry model at the scale of a single ice floe. For completeness, I did the same with a very high resolution (10cm) model I made from 3D photogrammetry on the same site. I then used this ‘validated’ parameter set to estimate sea-ice thickness for some larger regions.

Overall, the project changed direction three our four times, reshaping as we learned more – and really taking shape after some new methods for sea ice observations were applied in 2012.

What I discovered was that it is actually pretty feasible to do sea ice thickness mapping from a ship-deployed aircraft in the pack ice zone. This is important – because it means regions usually very difficult to access from a land-based runway can be examined.

I also showed that observations of sea ice so far may be underestimating sea ice thickness in certain ice regimes – and also likely to be overestimating sea ice thickness in others. This has pretty important implications for modelling the fresh water flux and other stuff (habitat availability) on the southern ocean – so more work is already underway to try and gather more data. Encouragingly, I showed that drill holes are actually quite accurate – and showed how some new approaches to the practice of in situ sampling might markedly increase the power of these observations.

The possibilities of a robotic total station and a mad keen field sampling nutter on an ice floe – endless! (we did some awesome work with a hacky sack and the total station, hopefully coming to light soon).

…and like all PhD theses, the last part is a vast introspection on where the soft underbelly of the project lies, and what could/should be done better next time.

Needless to say, I’m really relieved to be done. I go wear a floppy hat and collect my bit of paper next month.

What next? Subject the ice thickness work to peer review! Aiming for publication in 2017.

FOSS4G 2016 wrap-up

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I’ve recently returned from FOSS4G 2016 in Bonn, Germany. It was my first OSgeo conference, and it was quite amazing.

As a little background the OSgeo foundation supports the development of open source ‘geo software’, from desktop packages like QGIS to behind-the-scenes libraries (Proj.4) and even geospatial metadata catalogues (eg Geonetwork). My involvement? Over the years I’ve used parts of the OSgeo stack heavily. Increasingly. This also holds for the National Computational Infrastructure, so it made sense to submit an abstract and try to go.

My talk was going to be about storing and querying point cloud data from HDF files. Unfortunately I didn’t finish my experiments in time, and I ended up presenting a high level view of NCI, our point data storage and analysis needs, and some attempts at using Postgres-pointcloud and SPDlib (a HDF based point and waveform data storage system). This worked well with the session – until that time, most of the point data discussions at FOSS4G revolved around airborne or mobile LiDAR. It was nice to feel a bit like we had some unique problems to solve, and I feel grateful to be able to stand among the giants of OSgeo. In the same session, for example, were the developers of the PDAL and Entwine libraries – technical wizardry right there! I just try to keep up, and apply this stuff to jobs I need to do.

The main takeaway from the conference, however, is not the fact that I gave a talk. It was the amount of insight gained from the conference itself, and just being there. It was incredibly difficult to choose which sessions and workshops to attend, there were so many that were potentially useful for my life. I left feeling like I’d stepped into a seriously strong community of people who care about making great tools, and giving them away.

I chaired a session on web processing services, which was a new experience and really informative – especially Nis Hempelmann presenting on birdhouse services. This has seen immediate application in my work at NCI, so in the spirit of FOSS4G I’m running birdhouse, bugging the developers and have made my first ever commit on the project (a documentation typo – but you get the picture. Get involved).

Some other highlights were:

Ivan Sanchez’s lightning talk presenting what3fucks to the world. This actually has a serious point about how to divide the world into smaller pieces, and also how open software and data can be immediately applied, whereas closed-source options are not necessarily going to live as lively a life. If you build something and share it, it gets used.

Pretty much all of the keynote talks. Tomas Zerweck from Munich RE spoke about FOSS in risk management (which is all of us, science nerdlings, we are the boss of risk managers – without our field observation data, there is nothing). Oddly, every title slide showed Australia, and given our ignoble position as top consumers and chief backwards-pedalers of the world, I wondered if we are seen as a risk to be managed. Probably! Another standout keynote was Peter Kusterer, from IBM Germany, who described how the FOSS community got behind an emergency response to refugees arriving in Germany. Take note also Australia: Wir shaffen das!

 

In the regular programme – so much to choose from! I went to a discussion on open standards and open software, and was heartened to hear that small developers and big organisations with standards voting rights are happy working partners. I saw an excellent talk by Arnulf Christi on the relative permanence of data compared to software. Mind the data – words to live by, because there’s no point collecting all this information if nobody can use it in 3, 10, 50 years time. My brain was completely exploded by Olivier Courtin, on using postGIS in a real advanced way. Indeed. And I saw as many geoserver-related talks as I could, because it’s my job. But really, there was so much to choose from, and I will gradually catch all the videos of talks I would have liked to see. A colleague of mine just showed me another mind-blowing talk on geotiff.js and plotly that I would never have thought to go to. Here’s the programme:

http://2016.foss4g.org/schedule.html

…and you can download or watch all of the talks from the conference here:

http://video.foss4g.org/foss4g2016/videos/

So conference main work things done, here is a photo from the conference dinner – on a boat on the Rhine, with an accordion and cello. Later, after some beers and discussions of life and point clouds, I was dragged onto the dance floor and busted out my finest moves.

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…and here a couple of photos from the world conference centre, an amazing venue.

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The theme of the conference was ‘building bridges’ – and it certainly met those aims. There was a vast cross section of the spatial data community from insurance companies doing their due diligence about whether to switch to FOSS software stacks, to excited developers presenting brand new ideas. I was able to meet and speak to a number of people I’d only ever heard and read about – making that personal connection which always helps when we need to develop ideas into reality later.

I’m really grateful that I was able to go, and I’m already looking ahead to 2017, and what ideas I can convert into reality so that I’ve got something to bring to the community.

Finally, a side effect of the conference was catching up with an old friend I have not seen in 14 years!  We have surprisingly parallel lives – so what did we do? climbed rocks, of course!img_20160828_155707701

Hi Canberra

Spatialised has moved – I am now based in Canberra, and after a few months of moving and general hiatus I’m beginning the business of science, PhD’ing and spatial stuff once more.

So, greetings from Australia’s capital!

Spatialised is born

Hi everyone, and welcome to Spatialised! – a consultancy aimed at solving spatial analysis, problems.

I can help you with point cloud analysis and manipulation, photogrammetric modelling methods, airborne LiDAR problem solving, DTM, DEM and DSM production. See my toolkit page for an up-to-date list of my in-house capacity and what I can do using your software and hardware.

With experience drawn from four reseach voyages to the Antarctic pack ice zone, I can also offer logistical and OH & S support for data collection in remote areas.

I’m currently based in Adelaide, South Australia – I’m happy to work locally or for remote clients anywhere in the world. I hope I can help you solve your spatial problems.

Interesting spatial discoveries, news and updates will appear here as they come – you’ll find links to contact information, a bit about myself and my spatial toolkit in the menu bar above.

Happy trails!

Adam