Index: cf-conventions/trunk/docbooksrc/appendix-f.xml =================================================================== --- cf-conventions/trunk/docbooksrc/appendix-f.xml (revision 66) +++ cf-conventions/trunk/docbooksrc/appendix-f.xml (revision 48) @@ -13,7 +13,4 @@ be shared among several mappings, their definitions are contained in a table in the final section. - The attributes which describe the - ellipsoid and prime meridian may be included, when applicable, with - any grid mapping. @@ -26,10 +23,13 @@ describing map projections. + - - Albers Equal Area + + Albers Equal Area + grid_mapping_name = albers_conical_equal_area + @@ -71,17 +71,20 @@ + + + Notes: + + + Notes on using the PROJ.4 software package for computing the mapping may be found at http://www.remotesensing.org/geotiff/proj_list/albers_equal_area_conic.html. + + + + + + - - Notes: - - - Notes on using the PROJ.4 software package for computing the mapping may be found at http://www.remotesensing.org/geotiff/proj_list/albers_equal_area_conic.html. - - - - - - - + + + Azimuthal equidistant @@ -135,7 +138,11 @@ - - - + + + + + + + Lambert azimuthal equal area @@ -189,7 +196,8 @@ - - - + + + + Lambert conformal @@ -246,45 +254,18 @@ - - - - <emphasis role="newtext">Latitude-Longitude</emphasis> - -grid_mapping_name = latitude_longitude - - - This grid mapping defines the canonical 2D geographical - coordinate system based upon latitude and longitude - coordinates on a spherical Earth. It is included so - that the figure of the Earth can be described. - - - - Map parameters: - - None. - - - - Map coordinates: - - The rectangular coordinates are longitude and latitude - identified by the usual conventions - ( and ). - - - - - - - + + + + Polar stereographic - + + grid_mapping_name = polar_stereographic - - - - Map parameters: - + + + + + Map parameters: + @@ -306,7 +287,8 @@ - - - + + + + Map coordinates: @@ -327,9 +309,11 @@ - - - - - + + + + + + + Rotated pole @@ -337,4 +321,5 @@ grid_mapping_name = rotated_latitude_longitude + @@ -377,8 +362,8 @@ - - - - + + + + Stereographic @@ -435,8 +420,8 @@ - - - - + + + + Transverse Mercator @@ -493,85 +478,21 @@ - + + - - <emphasis role="newtext">Vertical perspective</emphasis> - -grid_mapping_name = vertical_perspective - - - - Map parameters: - - latitude_of_projection_origin - longitude_of_projection_origin - perspective_point_height - false_easting - false_northing - - - - Map coordinates: - - The x (abscissa) and y (ordinate) rectangular coordinates - are identified by the standard_name attribute - value projection_x_coordinate and - projection_y_coordinate respectively. - - - - Notes: - - Notes on using the PROJ.4 software packages - for computing the mapping may be found at - http://www.remotesensing.org/geotiff/proj_list/geos.html - . These notes assume the point of perspective - is directly over the equator. A more general description - of vertical perspective projection is given in - [Snyder], pages 169-181. - - - - - - - In the following table the "Type" values are - S for string and - N for numeric. - - - - Grid Mapping Attributes - - - - - + +
Grid Mapping Attributes + + + - Attribute - Type - Description + Attribute + Description - - earth_radius - N - - Used to specify the radius, in metres, of the spherical - figure used to approximate the shape of the Earth. This - attribute should be specified for those projected coordinate - reference systems in which the X-Y cartesian coordinates - have been derived using a spherical Earth approximation. If - the cartesian coordinates were derived using an ellipsoid, - this attribute should not be defined. Example: "6371007", - which is the radius of the GRS 1980 Authalic Sphere. - - - - false_easting - N + false_easting The value added to all abscissa values in the rectangular @@ -580,10 +501,8 @@ the unit of the coordinate variable identified by the standard name projection_x_coordinate. - - - + + false_northing - N The value added to all ordinate values in the rectangular @@ -595,6 +514,5 @@ - grid_mapping_name - N + grid_mapping_name The name used to identify the grid mapping. @@ -603,5 +521,4 @@ grid_north_pole_latitude - N True latitude (degrees_north) of the north pole of the rotated grid. @@ -610,33 +527,10 @@ grid_north_pole_longitude - N True longitude (degrees_east) of the north pole of the rotated grid. - - - inverse_flattening - N - - Used to specify the inverse flattening - (1/f) of the ellipsoidal figure - associated with the geodetic datum and used to approximate the shape - of the Earth. The flattening (f) of the ellipsoid - is related to the semi-major and semi-minor axes by the formula - f = (a-b)/a. In the case - of a spherical Earth this attribute should be omitted or set to zero. - Example: 298.257222101 for the GRS 1980 ellipsoid. (Note: By - convention the dimensions of an ellipsoid are specified using either - the semi-major and semi-minor axis lengths, or the semi-major axis - length and the inverse flattening. If all three attributes are - specified then the supplied values must be consistent with the - aforementioned formula.) - - - latitude_of_projection_origin - N The latitude chosen as the origin of rectangular coordinates for a map projection. @@ -646,5 +540,4 @@ longitude_of_central_meridian - N The line of longitude at the center of a map projection generally used as the basis for constructing the projection. @@ -652,23 +545,6 @@ - - - longitude_of_prime_meridian - N - - Specifies the longitude, with respect to Greenwich, of the prime - meridian associated with the geodetic datum. The prime meridian defines - the origin from which longitude values are determined. Not to be - confused with the projection origin longitude - (cf. longitude_of_projection_origin, a.k.a. central - meridian) which defines the longitude of the map projection origin. - Domain: -180.0 <= longitude_of_prime_meridian < 180.0 decimal degrees. - Default = 0.0 - - - longitude_of_projection_origin - N The longitude chosen as the origin of rectangular coordinates for a map projection. @@ -678,25 +554,10 @@ north_pole_grid_longitude - N Longitude (degrees) of the true north pole in the rotated grid. - - - perspective_point_height - N - - Records the height, in metres, of the map - projection perspective point above the ellipsoid (or sphere). Used - by perspective-type map projections, for example the Vertical - Perspective Projection, which may be used to simulate the view from - a Meteosat satellite. - - - scale_factor_at_central_meridian - N A multiplier for reducing a distance obtained from a map by @@ -708,5 +569,4 @@ scale_factor_at_projection_origin - N A multiplier for reducing a distance obtained from @@ -716,51 +576,11 @@ - - - semi_major_axis - N - - Specifies the length, in metres, of the semi-major - axis of the ellipsoidal figure associated with the geodetic datum and - used to approximate the shape of the Earth. Commonly denoted using the - symbol a. In the case of a spherical Earth - approximation this attribute defines the radius of the Earth. See - also the inverse_flattening attribute. - - - - - semi_minor_axis - N - - Specifies the length, in metres, of the semi-minor - axis of the ellipsoidal figure associated with the geodetic datum and - used to approximate the shape of the Earth. Commonly denoted using the - symbol b. In the case of a spherical Earth - approximation this attribute should be omitted (the preferred option) - or else set equal to the value of the semi_major_axis attribute. See also the inverse_flattening attribute. - - - - - standard_parallel - N - - Specifies the line, or lines, of latitude at which the developable map - projection surface (plane, cone, or cylinder) touches the reference - sphere or ellipsoid used to represent the Earth. Since there is zero - scale distortion along a standard parallel it is also referred to as - a "latitude of true scale". In the situation where a conical - developable surface intersects the reference ellipsoid there are two - standard parallels, in which case this attribute can be used as a - vector to record both latitude values, with the additional convention - that the standard parallel nearest the pole (N or S) is provided first. - - + + standard_parallel + Line of constant latitude at which the surface of the Earth and plane or developable surface intersect. This attribute may be vector valued if two standard parallels are specified. - Domain: -90.0 <= standard_parallel <= 90.0 @@ -768,5 +588,4 @@ straight_vertical_longitude_from_pole - N The longitude to be oriented straight up from the North or South Pole. @@ -775,6 +594,8 @@ - +
+ +