Updating and editing terrain datasets

For the most part, terrain editing is about editing features. You edit feature classes that participate in a terrain using standard edit tools. You can add, remove, and replace data referenced by terrains. This enables you to manage your measurement data over time, which is important, considering topographic and bathymetric projects often compile information over months and even years. A terrain dataset can grow as the data becomes available.

If a survey area needs to be updated with improved measurements, the new data can be swapped in. Minor edits don't invalidate the entire dataset. Only the affected areas need to be built, thus saving time.

In ArcSDE, terrain datasets support versioning. Multiple users can access different representations of the terrain for different projects. What-if scenarios are made possible by allowing design edits that model proposed changes to be made without actually changing the original surface. If the design is realized, the edits can be posted back to the source data.

Terrains can be edited to fix problems, make improvements, and increase or decrease their extent.

Terrain dataset edits fall into three broad categories:

• Edits to the terrain dataset schema
• Edits to measurements residing in regular feature classes
• Edits to measurements residing in embedded feature classes

Terrain dataset editing examples

From the application perspective, there are some common editing needs:

Common terrain dataset editing tasks

Task	Example
Expanding area of coverage over time	Appending new measurements as they become available (data acquisition is often staged over time with multiple data deliveries from a data provider). The data extent is expanded.
Quality assurance	Identifying and removing errors. Removing blunders representing individual measurements. Replacing areas containing systemic errors with corrected measurements.
Maintenance	Keeping the definition of terrain up-to-date. Replacing areas with new or updated information (for example, changes to landscape as a result of construction or natural forces). Replacing data with data of higher quality/accuracy.
What-if scenarios	Modeling proposed changes on the landscape (for example, related to drainage or viewshed). Replacing existing measurements with new ones. May be temporary or permanent.
Multiuser editing	Operators perhaps responsible for edits to all data layers within constrained areas (for example, all data per tile or map sheet). Operators perhaps responsible for edits to individual layers for unconstrained areas (such as all lidar data). Unusual for operators to modify same data layer for same area, although potential exists for conflict near common boundaries of assigned areas.

Types of editing