Map

The interactive map (based on Leaflet) is a tool to present and enter the location of places. PostGIS is used for creating and manipulating spatial data.

Navigation

• You can zoom in/out with the mousewheel or the +/- buttons in the upper left corner.

• You can drag the content with the mouse (left click and hold)

• Change the basemap at the layer button in the upper right corner.

• Switch to full screen with the rectangle in the upper left.

Search

With the magnifying glass icon in the upper left you can search for (current) places at GeoNames.

WKT import

With the icon a WKT text can be imported. Clicking this button will open a new popup where a WKT geometry can be entered. If the geometry is valid, the draw geometry button will be enabled. By clicking this button the geometry will be drawn on the map and the respective geometry popup will open to enter title and description for this geometry.

Possible WKT geometries with examples are:

• POINT(30 10)

• LINESTRING(30 10, 10 30, 40 40)

• POLYGON((30 10, 40 40, 20 40, 10 20, 30 10))

Adding new geometries

When in insert or update mode of a place you have following options available (can be combined):

• Set a marker/point at the position where the physical thing is located.

• Draw a line connected to a physical objects spatial characteristics, e.g. the course of a road.

• Draw the shape of a physical thing if the precise extend is known.

• Draw the area in which the physical thing is located. E.g. if its precise shape is not known but known to be within a certain area.

GeoNames

The GeoNames ID field can either be manually entered or imported from a map search result.

The checkbox exact match can be used if there is a high degree of confidence that the concepts can be used interchangeably. By default it is a close match, which means that the concepts are sufficiently similar that they can be used interchangeably in some information retrieval applications. Please refer to SKOS for further information.

Map Overlay

If you have the module map overlay activated in your Profile, added overlays for places will be visible on the map by default and can be toggled at map layer button at the upper right corner.

To insert new overlays (only available for editors and admins) go to the view of a specific place. After adding an image file in the file tab you can click link in the overlay column to enter coordinates (Easting and Northing) for:

• top left corner

• top right corner

• bottom left corner

of the image to position it on the map. The coordinates need to be in WGS84 decimal degrees (EPSG 4326).