Sony HKDW-704 Operation Manual page 142

Ephemeris data
Transmitted by each satellite, contains important information about the
status of the satellite, the current date, and the time.
Geodetic system
Standard used to indicate locations on the earth.
A
Global Geodetic System which is used all over the word is WGS 84.
The GPS satellite orbits have been referenced to WGS 84.
GLORIE
Global Location-related Exchange File Format
Format used to record locations on a memory stick.
GPS
Global Positioning System
A global positioning system based on 24 GPS satellites orbiting the
earth. This system is used for applications like car navigation and so on.
Hot start
A unit starts to calculate a location using both almanac data and
ephemeris data that have been collected. The calculation time is the
shortest among the three kinds of start.
MJD
Modified Julian Date
A calender starting from midnight (00:00:00) on 17 November 1858.
The relationship between MJD and the Gregorian calender is indicated
according to a formula as follows.
MJD = int [365.25y] + int [y/400] - int [y/100] + int [30.59 (m-2)] + d -
678912
where y = year, m = month, d = day and in the case of January and
February, m = m + 12, y = y - 1, also, int [ ] indicates a calculation
method where values after the decimal point are discarded.
A-14
Appendix