The data will change with respect to season, but you can't pick up things that people are doing in the landscape. With the launch of the Ikonos satellite, 1-meter data are becoming available. You see a lot of changes that can be associated with natural variability but also human impacts from construction, for example. These differences in scale also represent areas of the industry that have their own standards associated with them. A local scale, in which you are moving around urban environments, is usually associated with organizations that are concerned about real-time movement.
Some good examples are flight models, perspective viewing, and transportation or logistics problems.
In the course of trying to bring together these different scales in a global environment, with connections to models and to real-time data feeds, the issue really isn't so much at an individual discipline level, but working between disciplines. A key issue related to data is the timely availability and perishability of data. We are very excited about the launch of the new satellite systems, although this complicates things. The new imagery impacts not only resolution and viewing detail, but also the timeliness of the data. You're not going to get a lot of 1-meter data that are updated very frequently to show changes.