Topography is the ground profile under the cable. This is represented in Terrain by a feature (see Online Help for Terrain). A Terrain feature can be created by importing a traverse or map document from the Survey/Map module. You can also drape a feature over a terrain model by drawing with the mouse. Several features can exist in a Terrain file, the feature displayed the Profile/Cable Data Windows is defined in the Profile Window Options. Most commonly the Profile Window is set up to display the current feature; in this case, to select a profile for cable analysis, simply click on the feature in the Plan Window with the selection cursor (see Terrain Online Help for more information about selecting the current feature and displaying it in the profile window).