In this blog post, we’ll show you the tools OCAD offers for adding great base data to your mapping project—tools that help you determine your location in the field and allow you to identify and map terrain features, vegetation, and man-made objects.
As you’ll see at the end of this article, all of this base data can be used in the OCAD App to map efficiently and accurately.
LiDAR
If you have access to up-to-date LiDAR data, consider yourself lucky. With LiDAR data, you can create excellent base maps that not only allow you to pinpoint your location but also help you identify many map features.
OCAD calculates two types of Contour Lines: smoothed (green) and not-smoothed (blue). Use the not smoothed contour lines as a background during field mapping, which includes all the details. To draw contour lines on the PC, you can start with the smoothed contours and adjust them as needed using the Reshape function.
The Hill Shading Map reveals numerous terrain features that are not visible in the contour lines, such as roads, forestry tracks, gullies, small pits and knolls.
The Feature Map is similar to the Hill Shading Map, but also shows features that are close to the ground such as stones, walls, tree trunks, fences, or cars which were previously not or only poorly recognizable on background maps.
The Las Intensity Map helps you to distinguish between deciduous and coniferous trees.
The Vegetation Height Map shows vegetation features ranging from open areas (yellow) and ground vegetation (red) to dense vegetation (green), open forest (white) and high trees (blue). The latter can be particularly useful in open forest with few ground vegetation.
The Vegetation Base Map is similar to the Vegetation Height Map but focus more on the runabilty of the terrain.
GPS
GPS is another key tool for determining position, especially when there is no or insufficient Lidar data available.
If your mobile device does not have a built-in GPS module, or if the built-in module is not accurate enough, you can connect it to an external GPS receiver.
In the OCAD App, you can use GPS not only to determine your location, but also to directly capture sketches and objects
We recently published a comprehensive article titled GPS in Orienteering Map Map Making that provides information about GPS and its use with OCAD.
Cadastral maps
Detailed cadastral maps are particularly useful for sprint maps, and they often allow you to pinpoint your exact location and map many features such as buildings, roads or boundaries.
You can import cadastral maps into OCAD in various formats (Shape, GeoPackage, DXF) or load them as a WMS/WMTS background map.
Areal images / Orthophotos
In open terrain, aerial photos and orthophotos can help with positioning and recognizing objects that are not visible on cadastral maps.
You have the following options for loading a georeferenced aerial photo into OCAD.
- You can open the aerial photo as a background map.
- You can add an aerial photo (e.g. from Google Maps) using the Online Map Services feature.
- You can load a corresponding layer using the WMS/WMTS features.
Using the Background Maps and Tools in the OCAD App
Head out into the field with the best possible base map!
All of this base data can be used in the OCAD App to map efficiently and accurately. In the app, you can show or hide various base maps or symbols and show your current GPS position.
- You can easily show, hide or change the opacity of base maps in the Layers Panel.
- You can turn GPS on or off in the Positioning settings.
- You can also easily show or hide symbols (e.g. hide unsmoothed contour lines)
