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 35/36 would have transmitted this
information for the leap second added December 31, 1989
as follows:
Date Time
311289 235959
311289 235960
010190 000000
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 35/36 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.
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