User`s guide

R2012a
7-4
You can easily construct a reference ellipsoid object for most commonly used coordinate
systems, including all those supported by the almanac function and those included in the
EPSG/OGP Geodetic Parametric Dataset (which is used in connection with the GeoTIFF
Format). Similarly, you can construct reference sphere objects representing spherical
models of the Earth, Sun, Moon and planets.
wgs84Ellipsoid Function
Many users today work exclusively in the World Geodetic System of 1984 (WGS 84).
Along with many other roles, it serves as the native coordinate system the NAVSTAR
Global Positioning System (GPS). All that may be needed in this case is the new
wgs84Ellipsoid function, which returns a referenceEllipsoid object with property settings
appropriate to the WGS
ˋ84
ellipsoid.
Compatibility Considerations
In addition to the earlier “ellipsoid vector” representation, the following functions have
been extended to work with reference ellipsoid, oblate spheroid, and reference sphere
objects:
areaint, areamat, areaquad, axesm, azimuth, convertlat, defaultm, departure, distance,
ecef2geodetic, ecef2lv, elevation, ellipse1, eqa2grn, geodetic2ecef, gradientm, grn2eqa,
hista, lv2ecef, mapprofile, meanm, meridianarc, meridianfwd, mfwdtran, minvtran,
rcurve, reckon, rsphere, scircle1, scircle2, setm, stdist, stdm, track, track1, track2,
vfwdtran, vinvtran
An “ellipsoid vector” is a 2–by-1 double having the form [semimajor_axis eccentricity].
Ellipsoid vectors are not self-identifying, they do not have a name property, and
the length unit of the semimajor axis must be known and managed separately.) For
backward compatibility, these functions continue to support ellipsoid vectors as well as
the new representations.
referenceSphere, referenceEllipsoid and wgs84Ellipsoid provide superior alternatives to
the almanac function and should be used in its place going forward.
The etopo function now supports reading additional ETOPO1 data sets
The complete set of ETOPO1 supported data sets is as follows:
etopo1_ice_c.flt