WGS84 Class
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10/16/2008
This class contains information that describes a specific World Geodetic System (WGS-84) location on earth, as defined by semicircles.
The WGS-84 location is used by MSN Direct to send location-based services to the host device.
Syntax
class WGS84
Parameters
| Method | Description |
|---|---|
Returns the latitude of this WGS-84 location, in degrees. |
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Returns the latitude of this WGS-84 location, in semicircles. |
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Returns a human-readable string that specifies the latitude of this WGS-84 location, in degrees. |
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Returns a human-readable string that specifies the latitude and longitude of this WGS-84 location, in degrees. |
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Returns the longitude of this WGS-84 location, in degrees. |
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Returns the longitude of this WGS-84 location, in semicircles. |
|
Returns a human-readable string that specifies the longitude of this WGS-84 location, in degrees. |
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Returns true if this WGS-84 location object is equal to the specified WGS-84 location object. |
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Sets the latitude of this WGS-84 location, in degrees. |
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Sets the latitude of this WGS-84 location, in semicircles. |
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Sets the longitude of this WGS-84 location, in degrees. |
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Sets the longitude of this WGS-84 location, in semicircles. |
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Sets the latitude and longitude to 0, in semicircles, for this WGS-84 location. |
Remarks
The World Geodetic System (WGS-84) coordinate system is a global standard that plots locations on earth by using an earth-fixed global reference frame. WGS-84 provides coordinates in relation to the center of the earth, compared with latitude and longitude coordinates that are determined by ground-based mathematical calculations. WGS-84 also uses various parameters, such as the shape of the geoid, the earth mass, and gravity, to calculate coordinates with improved accuracy.
A semicircle is a unit of location-based measurement on an arc. An arc of 180 degrees is made up of many semicircle units; 231 semicircles to be exact. A semicircle can be represented by a 32-bit number. This number can hold more information and is more accurate for GPS systems than a simple longitude and latitude value. Semicircles that correspond to North latitudes and East longitudes are indicated with positive values; semicircles that correspond to South latitudes and West longitudes are indicated with negative values.
The following formulas show how to convert between degrees and semicircles:
degrees = semicircles * ( 180 / 2^31 )
semicircles = degrees * ( 2^31 / 180 )
If the MSN Direct receiver requests information about the current location of the host device, this information should be obtained by using GPS technology and then returned to the receiver in the form of a WGS84 class.
In MSN Direct services for Windows Embedded CE, the host device is the Windows Embedded CE powered device.
Requirements
| Header | DBRLib.h |
| Library | DBRLib.lib |
| Windows Embedded CE | Windows CE 5.0, Windows Embedded NavReady 2009 |