Monday, August 07, 2006

Google Earth Enterprise...

I have been using Google Earth Enterprise for a while- mostly from a consulting/developer/support role, not as someone that keeps a system running on a day to day basis. I also have to be careful with what I can and can't say about these things due to various agreements under which I am signed up.

Thus, it is cool to see someone who is a daily user blogging about it on a regular basis.

A recent post over there was asking about differences between working with GEE, versus other server GIS applications.

One point that I would add as a difference that takes a while for people that have a lot of experience in the ESRI world is that the build process is quite extensive. It takes quite a large amount of CPU cycles and disk space to build the base map data into the database- hence the reason for building the base data on some kind of weekly or greater frequency. (You use KML for stuff that changes frequently.) The payoff for this increased build time is the remarkable performance that users experience with the Google Earth application. Everything is really well precalculated for display, so you end up with a great user experience, at the cost of a not insignificant amount of labor on the back end to keep things moving. Still, it is something a lot of customers have taken some time to get their heads around, because they are used to expecting real time data in the base map. It's a very interesting architectural tradeoff analysis.

3 comments:

Ryan.Arp said...

Thanks for taking a look at my blog.

For my projects I usually update my shapefiles (in ArcView) weekly with a build command set up to run over the weekends (in GEE Server). Thus, all I have to do is edit and/or update my data, dump it into a build directory then publish the project/database on Monday, log back into the GE client in the morning to see the changes.

I would say build times range from an hour to two hours for my projects. If a project updates imagery often, your build time goes up considerably.

Matt M said...

It does take a while to update the imagery. I had some customers who wanted large imagery updates- daily. It took too long- had to be overlays. Fortunately, Google came out with Super Overlays.

One thing about imagery- you only get one image per area. That took some getting used to is that people who want different imagery types over an area can't do it in the basemap...you can't switch between them. One hack-around for that is to define the different image types at different zoom levels.

Ryan.Arp said...

Daily imagery updates would be brutal, although Super Overlays (I haven't heard of it) sounds interesting.

GEE supports multiple image overlays (via KML only from what you're telling me) but I would think you could add multiple server locations with images housed on each server address--that doesn't make very much sense.

Perhaps the GEE team is working on that one. I could see this as a problem for all sorts of raster overlays. While setting up the hack is reasonable, there really should be a way to toggle images.