Back to San Jose. We need Metadata.

In June, I OpenStreetMap’d suburban development in San Jose. I haven’t been back physically, but can check out the state of San Jose’s digital geography.

Reverse engineering the update schedule, provider and time source of imagery and vectors has become a kinda of amatuer geographer sport. Following Google’s last imagery update, construction cranes and shadows yielded, with fantasticals, a pretty precise date. Analysis of G-Y-M US Streets, with knowledge of Navteq/TeleAtlas data distribution, put Yahoo at 1-2 quarters ahead in street updates. In San Jose, I reckoned that someone on the construction crew could date the aerial imagery to the nearest week, based on how much orchard had been transformed into suburb.

There’s so much usefulness in knowing the temporal state of geographic data, people are willing to exert heroic geek effort to derive that metadata. However, it’s just untenable to reverse engineer the planet, especially when this information is well known to the data providers. This metadata needs to flow through the entire chain.
google-summer-winter
I was wandering Google Earth around Hetch Hetchy Resevoir, where I spent a week backpacking years ago. Multiple updates overlap this area, so summer discretely breaks to winter. Now this is almost accurate, we had a late spring snowstorm midtrip. But wouldn’t it be useful to see just summer, or just winter. It’s also necessary to have access to past data, to analyse change, the seasons, the global warming.

Back to San Jose. Yahoo is in the lead as well, with the streets as up to date as when I visited. However, they only updated their Map Layer, not the Hybrid view, where it’s still incomplete. And there’s still an error, showing the corner of Fowler and Yerba Buena Rd as passable, when it’s been blocked off. The aerial imagery hasn’t updated.

Old Farm Equipment and New Houses

Google is exactly the same as June, no road or aerial imagery update. MSFT is about the same, except they’ve added Bird’s Eye imagery for the area, so you can just about look underneath the trees adjacent to the old rusting farm machinery I photographed.

So generally, OpenStreetMap still reins for timeliness of the data, and transparency of when it was updated.

Timeliness, transparency, and responsiveness. It’s the biggest complaint of users and the big data producers are starting to see the light on user contributions. And people, in San Jose particularly, are starting to exert the democratic rights to knowledge of their world. Add in the question of cost recovery, it seems the only reasonable way to move ever growing public geodata needs forward is OpenStreetMap and GeoRSS.

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