This is an old revision of the document!

arc element

Attribute	Format	Remarks
Root Element	map
Element	arc
radius	float	radius of the arc in nautical miles
start	integer	start angle (method 1)
end	integer	end angle (method 1)
clockwise	boolean	Draw arc clockwise if “true” (default: true)
stroke_pattern	double array	line pattern described in an array of doubles
stroke_width	float	line width in pixels
stroke_color	string	color id name
fill_color	string	color id name

Use this element to draw an element with the shape of an arc. There are two methods available for building arcs :

Method 1 : Using center and start/end

Requires one <point> element to be the center of the arc. Requires start and end attributes to be set to the desired start and end angles of the arc (in degrees, range 0-360)

Example

  <arc radius="10" start="90" end-"270" clockwise="false">
      <point lat="N0505405" lon="E0042904"/>
  </arc>

Method 2 : Using 3 points

Requires three <point> elements. Builds an arc that centers on the first point and passes by the specified two other points.

AIS publications such as AIP's use three-point arcs to define lateral airspace borders. This method is especially designed to allow you to define exactly the same airspace in a map.

Example

Brussels CTR: 504434N 0043404E - an arc of circle, 10 NM radius, centered on 505405N 0042904E and traced clockwise to 505203N 0044435E - 504434N 0043404E.

  <arc radius="10" clockwise="true">
      <point lat="N0505405" lon="E0042904"/>
      <point lat="N0505203" lon="E0044435"/>
      <point lat="N0504434" lon="E0043404"/>
  </arc>

Back