Tuesday at 8:30 am far more people than I expected filled the first of two sessions on ESRI’s Community Basemap Program. Let’s start with the Q & A from that session, then go to questions I and readers had after our podcast on this topic.
Recall that ESRI is building a series of basemaps from community and commercial provider to be published as services for use in ESRI products, APIs and via ArcGIS Online.
These are questions (from the audience) and answers from Dean Kensock and Christophe Charpentier at the end of the presentation (both paraphrased).
Q: Might data contributed for one basemap (streets) be used in another (imagery)?
A: Yes, but we’d ask you if was ok, first.
Q: What about other layers (beyond, topo, imagery, streets)?
A: We are looking for feedback on that, but for now are focussing on these base layers. Among those suggested: parcels, historic imagery, imagery labels, trails.
Q: What about correcting errors in the data?
A: Easy ones are easy (like if a road goes off into the ocean). Others we’d need to go back to the provider. We do hope to one day include VGI to identify errors and corrections.
Q: What is commercial use? (The data is for non-commercial use only.)
A: If it’s not public facing, if it has ads, requires payment to see or supports indirect commercial activity (bringing people to your store, for example). Remember that you can make and share layer packages of your data on ArcGIS.com to share such things now.
Q: Printing?
A: 96 DPI for all the different scales, so there is some pixelation. Best to print them a bit smaller than true size.
Q: How do you deal with boundary issues, that is when two data sources conflict at or near a boundary?
A: We try hard to gain agreement on a boundary, then insure that no data from one source overwrites that of another.
Q: Will ESRI sign required contracts from public data providers?
A: Yes, but legal does not like it! One provider in Spain required that and ESRI complied.
Q: Can you make the agreement public (on the Web)?
A: Yeah, that’s a good idea? (My suggestion!)
Q: Can you use this for geocoding?
A: No, it’s just for display (it’s a tile cache at many different scales), but ESRI offers geocoding and routing services if you need them.
I sat down with with Product Manager Christophe Charpentier to tackle many other questions.
Q: What’s in the license contributors sign?
A: Basically, it says we can serve the data.
Q: Under what license do users provide ESRI the data?
A: We recommend Creative Commons, but are happy to use “their license” or any legal doc that explains their sharing practices. Basically, though, we are fine with any one that allows us to publish the data via Creative Commons.
Q: What about metadata and attribute? How is that handled?
A: Both are accessible in a list via ArcGIS.com and via the REST API for developers. They are by the “footprint” of the data contribution.
Q: How is the data served?
A: ArcGIS Image Service in tiles that match Googles and Bings. That’s now the de facto tiling scheme and ESRI supports it.
Q: Any other service options? Open standard ones like WMS perhaps under consideration?
A: Yes! Some governments are wary to provide data to us to publish via our service since it could be conceived as giving ESRI an advantage. They want other options, like WMS. In other cases, providers want WMS to serve the many platforms within their user base. Some are resolving this issue for the short time by republishing our ESRI service via their ArcGIS Server instance as WMS. [I think that’s called service chaining or a cascading service if I remember my OGC stuff correctly.]
Q: How many orgs are in the program now?
A: About 500 - worldwide! Most are ArcGIS Server users.
Q: Why do you think most are ArcGIS Server users? I’d think they’d NOT have ArcGIS Server, but need their data hosted.
A: Two reasons:
1) Orgs want to use their server to support specific apps for their users, not for publishing to the general public. This takes the burden off their server.
2) Putting their data onto our server in our standard form with neighboring data allows them to easily publish regional apps. They can even keep their local data in its own special data model, while publishing it via a basemap using our standard data model.
Q: Who are these basemaps for?
A: Our users are the first target users, but all GIS users can tap into it.
Q: Can others, say an Intergraph using city, contribute?
A: Absolutely.
Q: How many tiles are served per day?
A: 8 million
Q: How are updates handled?
A: The topo data is updated monthly and streets and imagery less often, about twice a year. The twice a year noted on the website referred to the release cycle of ArcGIS.com. We need to make that more clear.
Q: What’s the future of updating?
A: We want to open tagging of “errors” to everyone but give data owners the power to make edits directly via ArcGIS.com or by uploading data.
Q: What about making vectors available?
A: Right now serving up image tiles is a good “comfort level” for contributors. But in time, that may change.
