Latitude and Longitude attributes

All map elements require at least one <point> element which defines a geographical position on the map. In general a geographical point is defined as a latitude/longitude pair. If cartesian X/Y attribute values are used, the point is calculated using the <origin> given in the FIR configuration file (config.fir).

When a map is loaded all points defined as a latitude/longitude pair are transformed to cartesian X/Y values relative to the system origin point and stored as such internally. So using cartesian X/Y might slightly improve startup speed but keep in mind that in that case the system origin point cannot be changed.

Tip: Use predefined points in the points.xml file for specific navigation points. This will make your map definition more readable and especially easier to maintain.

The format of the latitude/longitude values is Zdddmmsssss where:

• Z = N or S for latitude, E or W for longitude
• ddd = degrees (3 digits, zero padded)
• mm = minutes (max 59)
• sssss = seconds with maximum 3 decimal places (max 59.999)

The predefined <point> elements are defined in the points.xml file. Use the id attribute to use a predefined <point> element.

latitude/longitude example:

• lat=“N0543000000” → N054:30:00.000
• lon=“W0033535000” → W003:35:35.000

The trailing zeroes are not required, the following is also valid: W003:35:35.000 → lon=“W0033535”

<point lon="N0543000000" lat="W0033535000"/>
<point lon="E0043127" lat="N0511038"/>
<point lon="E0043140" lat="N0511101"/>
<point ref=”REMBA”/>
<point ref=”EBBR-IAF-25L”/>