Check LiDAR elevation on the map

The elevation check reads the LiDAR ground height wherever you tap the map. Use it to see how much fall there is from a low spot to the outlet, or to sanity-check a high spot before you generate contours. It uses DEMs (LiDAR elevation surfaces) saved on the tablet, so it works offline on the module Wi-Fi.

Before you start

Time: a minute.

• At least one field with a saved DEM (Prepare Field or Fetch LiDAR DEM). Without one the button is hidden.
• You're on a Survey, Field Survey or grade map. The button isn't on the Levee or LiDAR & Mapping maps.
• Helpful, not required: the field's layers on the map, so you can see where you tap (Put a field's layers on the map).

Check elevations

Tap the height button

It's the top button in the column of dark square buttons at the bottom right of the map, just above the layers button. It has a green up-and-down arrow. Green means checking is off. A window called Select LiDAR Source opens.

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Tap the field's DEM

The window reads Choose a saved LiDAR DEM, then tap map points to check ground elevation. Each saved DEM is listed with its size and source. Tap the one for the field you're in.

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Tap a spot on the map

The height button turns amber, and a message along the bottom says Tap map points to check LiDAR elevation. While checking is on, map taps only read elevations.

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Read the bubble

Each tap drops a green bubble with the ground elevation there, in your units, for example 1069.10 ft. A brief ... shows while it reads. The next tap moves the bubble.

To stop: tap the amber button again

The Select LiDAR Source window opens with the DEM in use ticked.

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Tap Stop Checking

At the bottom of the window, next to Cancel. The button turns green and map taps go back to normal. In another field, tap the height button and pick that field's DEM instead.

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Reading the numbers

• Compare two spots, not raw numbers. LiDAR elevations come from the public survey's datum. Your GPS elevations depend on your base station and calibration, so the two won't match exactly. The difference between a low spot and the outlet is what counts.
• The LiDAR is a snapshot of the day it was flown. Ground cut, filled or built up since will differ.
• It is for planning. Survey and grade with RTK Fixed.

If it doesn't work