Tag Archives: Background Maps

The Strengths of WMS and WMTS

The terms WMS and WMTS may sound scary to people who are not very familiar with computers. But no worries: It’s pretty easy to use them and knowing their strengths is of great advantage for mapping and even for course setting.

So, what exactly is WMS and WMTS?

WMS (Web Map Service) and WMTS (Web Map Tile Service) are interfaces for retrieving geodata as raster data over the internet. More and more of these services are available today.

  • A WMS is calculated on the server side and delivers one image per request.
  • A WMTS delivers tiles that have been pre-renderd on the server side, and cached on the client side. This will reduce waiting time for the data and bandwith.

In OCAD, you can load WMS/WMTS as a background map. To do so, choose the WMS / WMTS command from the Background Map menu.

Typical layers are e.g. official cadastral surveys, topographic maps, aerial images, but also protected areas or forest reserves. All these data can contain useful information for your map project.

Therefore, you can easily update maps or add additional information to it with WMS/WMTS. In the example below, we connected a WMS from swisstopo and displayed a layer to show Forest Reserve Areas on a map.

Also, you can set courses on a WMS / WMTS layer. A step-by-step guide can be found in our OCAD Wiki.

Export of Geospatial PDF

When exporting a PDF from georeferenced OCAD maps, a Geospatial PDF (WGS84) according to ISO32000 is created automatically.

The Geospatial PDF can be loaded e.g. on a mobile phone in the app Avenza Maps as a map or it is possible to measure distances and request coordinates in Acrobat Reader.

Geospatial PDF

Multi-directional Hillshading

A hillshade is a shaded relief picture of the surface. Important for a hillshade is the position of the imaginary light source, which is taken into account for shading the image.

Normally, the direction of the light source is 315° (north-west). Since the Service Update 20.5.3, it’s also possible to choose the option Multi-directional. It is a composite image made up of four images in which the light source comes from different directions. Like this, the terrain is more realistically represented, and overexposed and nonilluminated areas of the map are more balanced.

In OCAD, Hill Shading can be created from the DEM menu or from the DEM Import Wizard.

Load Georeferenced Google Maps Aerial Images

Would you like to quickly and easily load a georeferenced aerial image as background map?

Then this is best done with the function Online Map Services. The function loads a Google Maps image directly at the right place.

This is how easy it works (Video you YouTube):

– Open the Online Map Services in the OCAD Background Map menu.
– Move and zoom in Google Maps to the desired extent.
– Load the image correctly geo-referenced as background map.

If the map is not geo-referenced, you need to adjust the Background Map afterwards.

Download Georeferenced Satellite Images

SAS.Planet is a free application used to view and download satellite images submitted by such services as Google Maps, Bing Maps, Yandex.maps, Yahoo! Maps and many more.

The satellite images can be downloaded and then loaded into OCAD as georeferenced background maps.

We can recommend the following workaround:

1. Download SAS.Planet from the web and run the application.

2. Zoom to your desired location and select an extend.

3. Open the Selection Manager and edit the tab Stitch. Don’t forget to create a file for georeferencing. We’ve chosen the settings as follows.

4. Start the download.

5. Open a map project in OCAD. Your map needs to be georeferenced. To georeference a new map, you can use the New Map Wizard.

6. Go to Menu Background>Manage>Open.

7. Choose your downloaded satellite images. As they most probably do not have the same coordinate system as your map project, you need to transform the satellite images. Choose Google Mercator as coordinate system.

8. Click OK and the satellite images appear as georeferenced background maps.