<Geographical Area Description> ::=
 <Point> |
 <Point with uncertainty circle > |
      <Point with uncertainty ellipse> |
 <Polygon> |
 <Point with Altitude> |
 <Point with altitude and uncertainty ellipsoid> |
 <Arc>;
<Point> : :=
 0000 <spare>(4)
 <Point horizontal co-ordinates> ;
<point horizontal co-ordinates> ::=
 <Latitude sign : bit> <Unsigned latitude : bit string(23)>
 <Longitude : bit string(24)> ;
<Point with uncertainty circle > ::=
 0001 <spare>(4)
 <Point horizontal co-ordinates>
 <spare bit> <Uncertainty: bit string(7)> ;
<Point with uncertainty ellipse> ::=
 0011 <spare>(4)
 <Point co-ordinates>
 <spare bit> <Uncertainty semi-major: bit string(7)>
 <spare bit> <Uncertainty semi-minor: bit string(7)>
 <Orientation of major axis: bit string(8)>
 <spare bit> <Confidence: bit string(7)>;
<Polygon> ::=
 0101 <Number of points>
 <Point co-ordinates>(val(Number of points)) ;
<Number of points> ::=
 0011 | 0100 | 0101 | 0110 | 0111 | 1000 | 1001 | 1010 |
 1011 | 1100 | 1101 | 1110 | 1111 ;
<Point with Altitude> ::=
 1000 <spare>(4)
 <Point horizontal co-ordinates>
 <Point vertical co-ordinate>;
<point vertical co-ordinate> ::=
 <sign : bit> <Unsigned altitude : bit string(15)>
<Point with altitude and uncertainty ellipsoid> ::=
 1001 <spare>(4)
 <Point horizontal co-ordinates>
 <point vertical co-ordinate>
 <spare bit> <Uncertainty semi-major: bit string(7)>
 <spare bit> <Uncertainty semi-minor: bit string(7)>
 <Orientation of major axis: bit string(8)>
 <spare bit> <Uncertainty altitude: bit string(7)>
 <spare bit> <Confidence: bit string(7)>;
<Ellipsoid Arc> ::=
 <1010> spare(4)
 <Point horizontal co-ordinates>
 <Inner radius: bit string(16)>
 <Spare bit> <Uncertainty radius: bit string(7)>;
 <Offset angle: bit string(8)>
 <Included angle: bit string(8)>
 <spare bit> <Confidence: bit string(7)>;
<Velocity Description> ::=
 <Horizontal Velocity> |
 <Horizontal and Vertical Velocity> |
 <Horizontal Velocity with Uncertainty>|
 <Horizontal and Vertical Velocity with Uncertainty>;
<Horizontal Velocity> : :=
 0000 <spare>(3)
 <Bearing: bit string(9)>
 <Horizontal speed: bit string(16)>;
<Horizontal and Vertical Velocity> : :=
 0001 <spare>(2)
 <Vertical direction : bit>
 <Bearing: bit string(9)>
 <Horizontal speed: bit string(16)>
 <Vertical speed: bit string(8)>;
<Horizontal Velocity with Uncertainty> : :=
 0010 <spare>(3)
 <Bearing: bit string(9)>
 <Horizontal speed: bit string(16)>
 <Uncertainty Speed: bit string(8)>;
<Horizontal and Vertical Velocity with Uncertainty> : :=
 0011 <spare>(2)
 <Vertical direction : bit>
 <Bearing: bit string(9)>
 <Horizontal speed: bit string(16)>
 <Vertical speed: bit string(8)>
 <Horizontal Uncertainty Speed: bit string(8)>
 <Vertical Uncertainty Speed: bit string(8)>;