Tutorial: Field surveys using Mergin Maps

2. Project preparation

To facilitate the changing of background maps, we can configure map themes in our QGIS project.

With map themes you can show only visible layers that are stored in a theme.

All our themes need the survey layer (Groundtruth) on top, followed by the Boundary layer.

We'll make map themes to show them on:

Let's start with the first one:

1. In the Layers panel organise the layers in such a way that Groundtruth is on top, followed by Boundary and then Sentinel_True_Colour.

2. Make sure that these layers are visible by checking the boxes and the others are not visible by unchecking the boxes.

3. Click the Manage Map Themes button

and choose Add theme...

4. Save the theme as Sentinel True Colour and click OK .

5. Repeat the steps for Sentinel_False_Colour. Make sure the layers are checked like this:

6. Do the same for OSM offline and OSM online.

7. If you now go to the Manage Map Themes button

you can see all themes and switch easily between the themes. Try it.

8. Save the project.

These themes can later be chosen in the Input app.