GLG Map Server Image Gallery

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Click here for more information about the GLG Map Server.


The GLG Map Server can render millions of points in every map requested by the user. This allows the Map Server to render many vector features such as roads, populated areas, lakes and rives, shorelines and a variety of other GIS data with an exceptional level of details.

The map server automatically switches layers based on the layers' zoom thresholds and the current zoom factor, and it uses a tile cache for faster rendering.
As the user zooms into an image the vector data will always appear crisp and precise regardless of the resolution of the image. The vector data is ideal for representing  elements such as cities, towns, roads and streets, populated areas, political boundaries, as well as other landmarks and areas of interests in a map image. A variety of vector formats are supported.

The image displays the Digital Chart of the World (DCW, VMAP0) vector data overlayed on top of the NASA's Visible Earth raster image. 
The US Census/Tiger data set contains a complete set of  GIS data for the entire US down to the street level details. It contains vector GIS data for states, counties, roads and streets, railroads, populated areas and other detailed information.

The Map Server's label layout negotiation ensures that labels do not obscure each other, and that labels with higher priority are not obscured by less significant labels.

When vector data is insufficient or detailed satellite imagery is available for a specific area, the raster image data may be used. Raster image data can greatly enhance the look and sophistication of a map image by providing vivid and colorful details to compliment the additional vector data (roads, etc.) overlaid on top of the image. The map server supports raster image data in a variety of raster image formats.

The NASA's Visible Earth raster data shown in the image are projected on the fly to the orthographic projection  to display the globe.


The Map Server can import the NITF and CADRG raster formats, which are often used for storing scanned maps and chart images. Setup files for hierarchically tiled datasets may be generated automatically using provided utilities.

The picture shows an example instance of Command and Control Technologies' C3I Surveillance Toolkit (C3iSTK) providing a Common Operating Picture for tactical surveillance and interdiction. Built with the GLG Toolkit and Map Server, it provides real-time tracking and geo-referencing of targets of interest, as well as point and click control and monitoring for a network of sensor systems. Click here for more CCT application images.

Elevation data is a special case of the raster image data which can be used to display elevation as color-coded thresholds or shaded relief image. It may also be used to query elevation of a particular point on the map. All major elevation data  formats can be imported.

In the picture, the shaded relief image generated from the elevation data in the DEM format is combined with the raster earth image to provide visual elevation feedback. The shaded relief images may be used with both raster and vector datasets.

The GLG Map Server supports both the Rectangular and Orthographic projections for rendering map images. The rectangular projection may be used to display the whole world and render the latitude and longitude lines in a more intuitive fashion. The orthographic projection may be used to render map image in the shape of the globe and to achieve a more realistic effect than the rectangular projection for top-level views.


When the map server is used with the GLG Toolkit, dynamic icons can be easily added on top of the map display. The Toolkit handles real-time updates of icon positions, selecting icons with the mouse, icon tooltips, changing icon shapes depending on the zoom factor and changing icon colors to show icon status. The map server is integrated into the GLG drawing as a GIS object, which can be edited with the GLG Graphics Builder for rapid prototyping.

The GIS Object may also be embedded in a bigger GLG application to handle the GIS portion of the graphics as shown in the second image. It shows a sample instance of the  Command and Control Technologies' RangeNet  control system.

Click here for more CCT application images.


The NIMA's Digital Chart of the World (VMap0,1,2 / VPF) data sets provides GIS information for the whole world and contains GIS data for countries, provinces, cities and populated areas, road and rail roads, bodies of water and other details.

In the image, the world cities data are displayed on top of the Digital Chart of the World, and
the NASA's Visible Earth raster image is used as a background.

The map server provides support for an unlimited number of layers. Layers are used to group various geographic features so they can be toggled on and off together in the map image. For example, roads and political boundaries are two possible layers. In addition, the attribute matching feature of the map server enables display of only the features inside a layer that have certain attribute values, allowing virtually unlimited customization.

In order to provide a visually pleasing and flexible look, the GLG Map Server supports 3 different alpha-blending modes and transparency. The use of alpha blending in map images can produce visually appealing transparent and partially opaque effects. For example, alpha blending can be used to render partially transparent weather and cloud maps on top of other vector or raster image data. Alpha blending can also be used to create transparent overlays over more important data.

When merely a simple change of color is not enough to satisfy the customization needs of a user, the GLG Map Server provides a unique system of attribute thresholding. Attributes of vector data can be automatically changed based on the actual data. For example, the size and color of a city marker can change based on the city's population. The label rendered next to the marker can include the city's name, population, lat/lon coordinates and any other attributes as shown in the image. Another popular example is the changing of line width and color of a road based on its type.

While many other available map servers on the market utilize complex relational databases and intricate setup procedures, the GLG Map Server provides a sophisticated hierarchical tiling mechanism for both image and vector data that is easily configured using ASCII setup files. When tiling is used, the Map Server loads only the tiles that are required for rendering a requested map area. The Map Server provides tiling utilities that may be used to automatically generate setup files for tiled datasets. The user can easily select which subsets of data will be used for a particular setup, using aliases to group sets of layers to be displayed.

The picture shows a tiled raster image with a verbose tile diagnostic output.

Many map server enabled applications will need to handle requests on both a global and small high detail scale. When a requested image includes raster image data, large amounts of data may be required in order to fulfill a request encompassing a large area. In order not to read and process an unnecessary amount of data, the GLG Map Server provides fallback layer support. When zoomed out sufficiently, a smaller image can be used instead of a more detailed one in order to optimize map server performance.

The GLG Map Server can operate both as a web-based GIS Map Server or stand-alone library API. In the stand-alone mode, the map server can be used as a library linked with a C/C++ program; this mode may be used for real-time applications installed on local machines that want to avoid using an Internet connection to access maps. In the web-based server mode, the map server can be used to provide images to a Java, C/C++/C# or ActiveX clients without a need to install GIS data locally. The web-based map server complies with the OpenGIS standard.

The GLG Map Server utilizes its own engine for rendering primitives such as images, polygons and text. As a result, map images generated on various platforms are guaranteed to be identical. Also, due to its independence of the underlying windowing system, the map server runs on both Unix/Linux and Windows platforms, and can be used on any headless server.