Archive for January, 2008|Monthly archive page

Crowdsourcing for Seismic Surveys

Every weekday afternoon around 5pm or so, the quarry several miles from my house blasts away a new layer of limestone. Whenever I feel the slight tremor from the blast, I feel as if valuable data is going uncollected. Could this data somehow be used to make a 3D model of the Edwards Aquifer?

An overlooked aspect of a GPS receiver is the highly accurate clock it contains. It seems like GPS receivers (and their clocks) could be attached to low-cost seismometers. The common clock of the GPS would allow independently collected data to be synthesized. I wonder if there might be enough geo-geeks in my neighborhood to build and deploy an array of these. There’s another quarry about 10 miles away, where I presume they also blast, so not all blasting signals originate from the same location. There will also soon be a lot of highway construction starting in this area, which will likely involve yet more blasting. Once the data is collected, it could be forwarded to a central site for processing. With all the recent innovations in oil exploration seismic processing, it seems like this data could be continually synthesized for model refinement. I’m not a seismologist, but would be interested in hearing from one regarding the plausibility of this.

While the geologists over at Edwards Aquifer Authority have done an fine job, it would be nice if they could build some detailed 3D models and serve them out on the web.
Edwards aquifer


The Unbearable Lightness of Being a Plumber

In his book The Unbearable Lightness of Being, Milan Kundera makes an interesting case that kitsch is the absolute denial of shit. Lately I’ve wondered if this implies other activities that deny the existence of shit are really exercises in kitsch creation.

Is Linq Kitsch?
Google for linq and plumbing and notice how many hits you get. Plumbing code is discussed with a sort of subtle condescension. The message is that plumbing is dirty, uncreative work – something better not thought about, hidden below the surface.

While Linq looks exciting, I wonder if we run the risk of abstracting the database to the point we overlook solutions requiring an understanding of internal design. Will someday our children forget the obvious solution: sometimes you just need to jiggle the handle after flushing objects (rows). Linq must be smart, but I can’t help but think there must be cases where plumbing your own O/R mapping might work better. It’s really not that bad, if you’ve ever played around with piecing together PVC pipe you probably realize that plumbing can actually be fun, with lots of room for creativity.

And it’s not just programming, but other aspects of GIS. Physicians seem to get credit for the longer lifespans we enjoy these days, but I wonder if more credit is due to plumbers. John Snows’ cholera maps revealed a plumbing problem. As far as I can tell he wasn’t using medical knowledge so much as taking on the role of a plumber and recognizing that, yes, shit does truly exist.

But beyond Snow’s maps, sewer datasets receive little attention. Could it be our kitsch sensibilities prevent us from publishing them on the web? Where I live there is a sign saying “Entering Edwards Aquifer Recharge Zone”, but never a sign that says “Warning Sewer Line is Here”. Last year a road construction crew broke a sewer pipe over the aquifer. They reported it twice. It leaked for a couple of weeks as the bureaucrats bungled through what could best be described as kitsch performance art: two different agencies denying the existence of the sewer line. Maybe we need more sewer museums to combat the kitsch, and give plumbing the respect it deserves.

Zillow, CrowdSourcing and MapCruncher

Shortly after Zillow announced they are releasing their neighborhood boundaries, The Virtual Earth blog described how this data can be chopped up by MapCruncher into tiled vectors for more efficient display.

I don’t see a realistic editing workflow though.

Let’s pretend I’m a realtor with in-depth knowledge of the boundary for a particular neighborhood and would like to edit Zillow’s boundary. Let’s assume my web map editing skills are limited to editing polygons in Google’s My Maps.

Editing the Neighborhood
I would like to go to a Zillow Web map displaying the neighborhoods (as vector tiles), choose a neighborhood, provide a Google My Maps account URL and click a button that says “edit”. Zillow would then would forward the outline of the selected neighborhood to My Maps account. I would then edit the neighborhood polygon using My Maps editing tools.

Is Google exposing My Maps in their API? When I search the Google Maps API reference for “My Maps” I don’t see anything. It would be great if I could leverage it as an editor.

Updating the Tiles
After editing the neighborhood I would then go back to the original neighborhood at the Zillow site submit the My Maps URL and click “Update”. Zillow would then retrieve the edited polygon, review it, and submit it to a MapCruncher queue. The MapCruncher process would read the queue and update the affected tiles. Maybe they could include a URL to my realty site in exchange for me improving their data. An edit history list could also be maintained.

HPC Cluster for MapCruncher
Granted there would probably not be a lot of updates to this dataset, but if there were, I think the MapCruncher queue would quickly fill up. I wonder if MapCruncher could be deployed to a cluster using Windows HPC Server 2008 cluster. If such a system could be implemented, it seems like, for example, a crowd of appraisal districts could be harnessed to maintain tiled vectors of parcels across an entire state.