About Specifying Longitude and Latitude Coordinates

In a Trapeze4 map database, longitude and latitude coordinates are specified for the ends of each street segment and for segment shape points. Coordinates are specified in accordance with WGS (World Geodetic Standard) 84.

Map files such as ArcInfo/ArcView shapefiles support various coordinate systems. However, only longitude and latitude coordinates can be loaded with MapMaker. If the data comes with other coordinate types, they must be converted to longitude and latitude before they are loaded into the Trapeze4 map database.

Coordinates in Trapeze4 map data are saved as degrees and decimal parts of degrees, rather than as degrees, minutes, and seconds. Before loading map data using MapMaker, Trapeze recommends saving coordinates as degrees and decimal parts of degrees.

In the Trapeze4 map database, latitude and longitude coordinates are saved as integers with an implied precision of six decimal places. For example:

• 46º 30’ 30’ = 46.50833333333º and is represented as 46508333 in the Trapeze4 map database
• 46º 30’ 0’ = 46.5º and is represented as 46500000 in the Trapeze4 map database

When loading flexible format data into the Trapeze4 map database, the system can convert latitude and longitude coordinates to the required coordinate system and precision.

You can also convert map coordinates using the Coordinates Tool in MapMaker.