Global Positioning System Almanac Data (Alm); Global Positioning System Fix Data (Gga) - Garmin GPS 25 LP Technical Specification

and time of day for leap second correction follow the guidelines in "National Institute of
Standards and Technology Special Publication 432 (Revised 1990)" (for sale by the
Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.,
20402, U.S.A.).
When a positive leap second is required, the second is inserted beginning at 23h 59m
60s of the last day of a month and ending at 0h 0m 0s of the first day of the following
month. The minute containing the leap second is 61 seconds long. The GPS 25LP
would have transmitted this information for the leap second added December 31, 1989
as follows:
If a negative leap second should be required, one second will be deleted at the end of
some UTC month. The minute containing the leap second will be only 59 seconds
long. In this case, the GPS 25LP will not transmit the time of day 23h 59m 59s for the
day from which the leap second is removed.
4.2.3

Global Positioning System Almanac Data (ALM)

$GPALM,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>,<15>
*hh<CR><LF>
Almanac sentences are not normally transmitted. Almanac transmission can be
initiated by sending the sensor board a $PGRMO,GPALM,1 command. Upon receipt of
this command the sensor board will transmit available almanac information on GPALM
sentences. During the transmission of almanac sentences other NMEA data output will
be temporarily suspended.
<field information> can be found in section 4.1.1.
4.2.4

Global Positioning System Fix Data (GGA)

$GPGGA,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,M,<10>,M,<11>,<12>*hh<CR><LF>
<1> UTC time of position fix, hhmmss format
<2> Latitude, ddmm.mmmm format (leading zeros will be transmitted)
<3> Latitude hemisphere, N or S
<4> Longitude, dddmm.mmmm format (leading zeros will be transmitted)
<5> Longitude hemisphere, E or W
Date
311289
311289
010190
Time
235959
235960
000000
22