Section 3 - Template 10 : Mercator

Octets Key Type Content
15 shapeOfTheEarth codetable Shape of the earth (see Code Table 3.2)
16 scaleFactorOfRadiusOfSphericalEarth unsigned Scale factor of radius of spherical earth
17-20 scaledValueOfRadiusOfSphericalEarth unsigned Scaled value of radius of spherical earth
21 scaleFactorOfMajorAxisOfOblateSpheroidEarth unsigned Scale factor of major axis of oblate spheroid earth
22-25 scaledValueOfMajorAxisOfOblateSpheroidEarth unsigned Scaled value of major axis of oblate spheroid earth
26 scaleFactorOfMinorAxisOfOblateSpheroidEarth unsigned Scale factor of minor axis of oblate spheroid earth
27-30 scaledValueOfMinorAxisOfOblateSpheroidEarth unsigned Scaled value of minor axis of oblate spheroid earth
31-34 Ni unsigned Ni - number of points along a parallel
35-38 Nj unsigned Nj - number of points along a meridian
39-42 latitudeOfFirstGridPoint signed La1 - latitude of first grid point
43-46 longitudeOfFirstGridPoint signed Lo1 - longitude of first grid point
47 resolutionAndComponentFlags codeflag Resolution and component flags (see Flag Table 3.3)
48-51 LaD signed LaD - Latitude(s) at which the Mercator projection intersects the Earth (Latitude(s) where Di and Dj are specified)
52-55 latitudeOfLastGridPoint signed La2 - latitude of last grid point
56-59 longitudeOfLastGridPoint signed Lo2 - longitude of last grid point
60 scanningMode codeflag Scanning mode (flags - see Flag Table 3.4)
61-64 orientationOfTheGrid unsigned Orientation of the grid, angle between i direction on the map and the equator (see Note 1)
65-68 Di unsigned Di - longitudinal direction grid length (see Note 2)
69-72 Dj unsigned Dj - latitudinal direction grid length (see Note 2)
73-nn pl unsigned List of number of points along each meridian or parallel (These octets are only present for quasi-regular grids as described in notes 2 and 3 of GDT 3.1)
Notes:

( 1) Limited to the range of 0 to 90 degrees; if the angle of orientation of the grid is neither 0 nor 90 degrees, Di and Dj must be equal to each other.

( 2) Grid lengths are in units of 10-3 m, at the latitude specified by LaD.

( 3) A scaled value of radius of spherical Earth, or major or minor axis of oblate spheroid Earth is derived from applying appropriate scale factor to the value expressed in metres.