Geodatenformate

In dieser Kategorie werden Geodatenformate für Raster- und Vorktordaten beschrieben, die in den Geopublisher importiert werden können.

AtlasStyler WFS

The OGC Web Feature Service (WFS) standard is a protocol that allows to query and transport spatial vector data over the network. It has been designed to overcome the proprietary protocols of different GIS vendors and to create a new level of interchangeability.

Connect AtlasStyler to WFS

Since version 1.6, AtlasStyler can connect to WFS servers and directly create SLD styles for their layers. Start AtlasStyler and use the import wizard:

There you can define variouse aspects of the server:

In the third and last step you may choose one of the advertised WFS layers:

The layer is then added to the AtlasStyler map and you may start creating a style by clicking the tool icon of the layer and select Style:

Tipps and Tricks

The WFS implementation of AtlasStyler has only been tested with Geoserver 2.0.2+, and bit with deegree 3.

Default namespace/workspace problem with GS 2.0.2

We experienced troubles with some Geoserver 2.0.2 installations, complaining that no default namespace would have been defined - even though it has been defined. The hack we found working:

  1. Log into the Geoserver with admin rights.
  2. Create a new dummy workspace and set it default.
  3. edit you existing workspace and set it default again.
  4. Delete the dummy workspace again.

After that, the connection worked flawless even without the need to restart Geoserver.

Mixed geometry types

AtlasStyler - with a history of styling Shapefiles - has problems when a WFS returns GML data which contains polygons, lines and points mixed. The quick solution in AS 1.6 is to treat that kind of "mixed geometry" as polygons. If you need propper support to style more complex GML, please contact wikisquare.de and lets look for funding. See also this piece of Geoserver WFS documentation: Dealing with mixed geometry types.

GeoTiff raster file format

GeoTIFF raster format

The GeoTIFF raster format is very flexible and is the preferred format to import rasters into Geopublisher. Some of the great features of GeoTIFF are for example:

  • The definition of the coordinate reference system can be stored inside the .tif file - hence no extra .prj projection definition file needed.
  • Ground Control Points can also be stored inside the .tif file - hence no extra world files are needed.
  • Any number of bands can be stored in one .tif file.
  • Colortables for one-band images can be stored iside the .tif file.
  • Multiple prescaled overviews of the same image can be stored inside one .tif file (see gdaladdo).

Import GeoTIFF into Geopublisher

Any GeoTIFF file can just be imported into the datapool.

Projection

Geopublisher will search the following locations in order to find projection information for a GeoTIFF:

  1. Ideally a GeoTIFF contains its projection information inside the .tif file. Geopublisher will first look there for a projection definition.
  2. Geopublisher will look for a .prj file with exactly the same basename (case-sensitive!). Read here about the format of .prj files.
  3. If no projection information is found, Geopublisher will still import the GeoTIFF. A message appears saying that the default coordinate reference system was assumed for the GeoTIFF. See here how to define the standard CRS for your atlas.

Colorization

A GeoTIFF raster can contain information about the colorization inside the .tif file - or not. It the information is contained, it will be used by Geopublisher automatically. Depending on the type of color information, you may import color information using the gdalinfo tool.

If no color information is contained in the .tif, Geopublisher can still be used to create such information using the SLD standard. Note that as of version 1.7, Geopublisher can only create working SLD styles for one-band raster files.

To style a GeoTIFF (or any raster layer) in Geopublisher import the layer into a map and click on the tool () icon. Then select style from the menu. The AtlasStyler editor dialog will open.

Externe Links mit Informationen zum GeoTIFF Format

 

.PRJ projection definition files

.prj files define the coordinate reference system for a set of geodata (e.g. a GeoTIFF or ESRI Shapefile). The files contain plain ASCII text and can be edited with any text-editor (e.g. notepad++).

Inside the .prj file, a textual definition of the projection in the OGC WKT format is expected.

If you know the EPSG-Code for a geodataset - but not the WKT definition - you can look it up at spatialreference.org and download the WKT definition there as a .prj file. This for example, is the .prj file for EPSG:4326.

SLD / Symbology Encoding

The OGC Symbology Encoding (SE) standard has initially been a part of the Styled Layer Descriptor (SLD) 1.0 standard. In august 2007 the OGC declared the separation of the standards (ext. link). Since version 1.1 the SLD standard only describes the styling-related communication with OGC webservices. The actual syntax for the description of styles got a new name: OGC Symbology Encoding 1.1 (SE).

Styled Layer Descriptor (SLD) is still widely-used as a synonym for Symbology Encoding (SE). The common filename postfix is: .sld

AtlasStyler is graphical editor that allows to create maps and export their symbology in form of .sld files.

Links to the SLD support and documentation of some WMS implementations: UNM Mapserver, Geoserver and Deegree.

Syndicate content