Getting elevation data

Contours come from a "surface" — the elevation of the field. The Levee source panel offers six data routes (plus Load Saved Job under Continue previous work); the same actions live in the sidebar when no contours are loaded yet.

1. Survey the field by driving (Survey New Field)

Drive the field yourself and the app records ground elevation as you go, then builds the surface from your track. This is the Drive to Map path. Drop a benchmark, drive back and forth to cover the field, and save. Best when you have no existing data and a clear field to drive. Covered in detail under Surveying a field by driving.

2. Import a GeoTIFF (GeoTIFF DEM)

A GeoTIFF is an elevation raster — a common output from drone mapping and survey software. Tap GeoTIFF DEM and pick the file. Because GeoTIFF files do not always say whether their elevations are in meters or feet, the app asks you in the contour settings dialog — pick the right one so the contour spacing comes out correct.

3. Load a saved LiDAR DEM (Saved LiDAR DEM)

The fully offline LiDAR route. Tap Saved LiDAR DEM to load a DEM previously saved by the LiDAR & Mapping workflow — no internet needed, and no source-units question (saved DEMs are always meters). The picker lists each saved field with its acreage and m/px resolution. If none exist, the app says No saved LiDAR DEMs found. Use LiDAR & Mapping while online to save one first. Contours are no longer built directly from a download inside the Levee screen.

4. Open LiDAR & Mapping (fetch a DEM while online)

Tap Open LiDAR & Mapping to switch to the LiDAR & Mapping screen in Save-LiDAR-DEM mode (a snackbar reminds you: Draw and save a LiDAR DEM, then reconnect to the controller and load it from Saved LiDAR DEM.). Internet is required there — draw the boundary, save the DEM, then come back to Levee and use Saved LiDAR DEM. The matching sidebar button is labeled LiDAR and does the same redirect. This route is gated behind the one-time real-controller unlock — if it is locked, connect to your module once to unlock it.

5. Load a saved survey (Saved Survey)

If you (or someone) surveyed this field before with the tablet, tap Saved Survey and pick it from the list. The app rebuilds the surface from the saved points.

6. Import a point file (Point File)

A plain text file of points — latitude, longitude, elevation per line (XYZ). Tap Point File and pick it. The app previews the first few lines and lets you confirm which columns are which and whether the elevation is in meters or feet. It accepts comma, space, tab, or semicolon separated files. The app fills the gaps between your points to make a continuous surface.

Whichever source you use, the next steps are the same: confirm a boundary, set the interval, and generate.