User`s guide

Chapter 3 - Receiver Descriptions
Millisecond to Degree Conversion
The primary output message of M12+ receiver in Motorola binary mode is the 12 Channel
Position/Status/Data Message (@@Ha). In this message, the latitude and longitude are reported
in milliarcseconds, (or mas). An example of converting mas to degrees is illustrated below.
One degree of latitude or longitude has 60 arcminutes, or 3600 arcseconds, or 3,600,000
milliarcseconds. To convert the positive or negative milliarcseconds to conventional degrees,
minutes, and seconds follow this procedure:
1. Divide the mas value by 3,600,000
The integer portion of the quotient constitute the whole degrees
2. Multiply the remaining decimal fraction of the quotient by 60
The integer portion of the product constitute the whole minutes
3. Multiply the remaining decimal fraction of the product by 60
The integer portion of the product constitute the whole seconds
4. The remaining decimal fraction of the product constitute the decimal seconds
CONVERSION EXAMPLE: Michigan Avenue, Chicago, IL:
Latitude = 150748869 mas Longitude=-315445441 mas
1. Latitude: 150748869 mas / 3600000 = 41.87468583
Longitude: -315445441 mas / 3600000 = -87.62373361
Whole Degrees of Latitude = 41, Whole degrees of Longitude = -87
2. Latitude: 0.87468583 * 60 = 52.48114980
Longitude -0.62373361 * 60 = 37.42401660
Whole Minutes of Latitude = 52, Whole Minutes of Longitude = 37
3. Latitude: 0.48114980 * 60 = 28.86898800
Longitude: -0.42401660 * 60 = 25.44099600
Whole Seconds of Latitude = 28, Whole Seconds of Longitude = 25
4. Decimal seconds of latitude, = 0.868988,
Decimal seconds of longitude = 0.440996
The decimal seconds of both latitude and longitude are then truncated to 3 decimal places, giving
a final result of:
Latitude = 41º 52'28.869" Longitude = -87º 37'25.441"
Motorola GPS Products - M12+ User's Guide Revision 6.X 09FEB05
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