Quick guide
Click here for the first steps with the system

Navigate through the map
Select the appearance of the map
Calculate the local gravity
Gravity zones for weighing instruments
Find more help

North America South America Europe Africa Asia Oceania
Map extent
West OK East
Map properties
Map projection
Map grid
Map size (Pixel)

   Selection of map layers
Team Base map
  Team unicoloured
  Team Terrain Shaded
Team Terrain
   Team Background (default)
   Team Contour lines
Team Gravity
   Team Background
   Team Contour lines
Team Geoid
   Team Background
   Team Contour lines
Team Gravity anomalies (free air)
   Team Background
   Team Contour lines
Automatic Manual

Team   Team Int. border lines
Team   Team Rivers
Team   Team Lakes
Team   Team Roads
Team   Team City >1.000.000
Team   Team City > 500.000
Team   Team City > 100.000
Team   Team City > 10.000
Team   Team City > 5.000
Zoom to your desired map area. Large areas may require more time for loading !
Select the thematic layer (optional with contour lines)
Press REFRESH-Button to activate the new map

   Local gravity
The local gravity may be calculated for a certain location or as an approximation for a city
If the coordinates are not known, simply click into the map at the favoured location


Team Zoom to the location
Team Start automatically by click into the map

Name or first letters...

   Optional search criteria
Search in this map section

No results !

  Gravity zone localisation
Choose your desired map area with the navigation tools
Determine the type of weighing instrument (Class,... ) that is designated for the gravity zones
Optional: The location of main interest can be prechosen with a starting point (by a click into the map). The zones will be developed around this point.

Weighing instrument specifications


Map grid resolution
coarse fine
Optional specifications

Point of main interest (start value)
longitude: latitude:
Max. height of the zone(m):
default (1800m):
background with shaded terrain

Click on the 'Distance'-symbol to activate the function
Select the start and the end point in the map
In order to start a new measurment: Press ESC key
Total distance:  %s km

Click on the 'Area' symbol to activate the function
Select the points in the map. Close the area by clicking on the first point again.
In order to start a new measurment: Press ESC key
Surface : %s km²


The Gravity Information System

First steps

Overview (Key Map)

The key map serves as a survey of the map navigation.
A red square or a small cross shows the particular position of the main map on the world map.
By a mouse click into the key map you can select a continent that will be loaded in the main map.

Continent selection

Instead of clicking into the key map you can also select a continent from this selective list. It is recommended to start the map navigation with a continent since it gives a better survey and it saves some loading time.

Map extent

The four input fields (North, West, East, South) indicate the particular extent of the main map in geographical coordinates [º].The 'North' and the 'South' give the minimum and maximum latitude, the 'West' and the 'East' specify the extreme values for the longitude.
The fields will be refreshed automatically after selecting a new map area.

To select a certain map area by coordinates change the values manually and click the OK-button.

Map size

The rectangle of the main map is set to a medium size of 600*420 pixel by default. With this map size the full view of this web page is optimized to a monitor resolution of 1024*768 or 1152*864.
If you use a different monitor resolution and the main map appears to be too small or too large then you can fit the map size by selecting a value from the drop down list.

It is recommended to zoom in to a smaller area at first to lessen the loading time.

Map legend

The map legend appears in an extra box below the main information box on the left hand side. It includes the main information about the thematic background layer with a coloured scale and the optional contour lines.
Further information to the map can be found in the upper right corner of this page with the map coordinates to the mouse pointer and with an approximated scale factor. Below the main map a scalebar in metric units may used to estimate distances.
The appearance of the map can be changed under the topic 'Map layer'.

Selection of a thematic layer

The basic illustration of the main map can be configured by the selection of a thematic layer.
In order to select a thematic background click on a symbol from the layer's list and mark the white box . This setting clears the previous background selection since only one background can be set. If the present background marker is cleared the Base map layer is selected automatically.

Activate the new settings by pressing the REFRESH button below.

The selection of a contour line layer is optional but it can only be one of these layers set per map view.

Selection of topo layers

The box Topo layer contains a list of map features that illustrate the local topographical or political chararcteristics.
By default the single features are activated or deactivated automatically depending on the map scale.


City search


Selection of the type of instrument

Optional inputs


Measuring a distance

Otaining an area

Zoom in

Zoom out

Recenter the map

Full extent

Thematic map layer

Gravity point selection

Approx. gravity for a city

Gravity zones for weighing instruments

Calculation of distances

Calculation of areas

Gravity data

Height data

Map data

Math procedures


Based on the structure of Cartoweb3 and the concept of UMN Mapserver

Created by Andreas Lindau, 2006
Visitors (sessions)
zoomin zoomout Move Maplayer   LocalGravity CitySearch GravityZone   distance surface   Help
Longitude Latitude
...may take a few seconds
  Background layer: Terrain
  Contour lines: none   

  0 8000  
Scale    1  :   189 300 000