# Topography and elevation (DEM)

> Request elevation for your project area once — 3D terrain and automatic elevations follow.

Source: https://geodb.io/guide/topic/topography_dem/ · Category: Getting set up
A digital elevation model (DEM) gives your project a ground surface. With
one in place, the 3D viewer drapes real terrain under your drillholes, and
records that arrive without an elevation can take one from the surface
automatically.

## Requesting elevation data

Open the **elevation page** and request coverage for your project area —
geoDB fetches public elevation data for the extent you choose and
processes it in the background; you'll see the dataset appear in the list
when it's ready. Larger areas take longer; you don't need to keep the page
open.

## Bringing your own

Have a better surface — a LiDAR-derived DEM or a drone survey? Upload the
GeoTIFF instead. Project files accept large rasters, and the 3D viewer
uses the highest-resolution surface available.

## What uses it

- **The 3D viewer** — terrain under traces, collars and geology.
- **Elevation fill-in** — collars and samples imported without an
  elevation value can be assigned one from the surface.
- **Sections and strip logs** — anywhere depth meets the ground surface.

One request, early in the project, and you never think about it again.