what constitutes the nav msg of GPS?
another question...
Which of the following data, in addition to the Pseudo Random Noise (PRN) code, forms part of the so called Navigation Message transmitted by NAVSTAR/GPS satellites?
a)Time; data to impair the accuracy of the position fix (Selective Availability SA)
b)Almanac data; satellite status information
c)Data to correct receiver clock error; almanac data
d)Time; position of the satellites
answer given is B I wonder what is wrong with D? an excerpt from oxford ATPL says:-
The information contained in the nav and system data message is:
SV position
SV clock time
SV clock error
Information on ionospheric conditions
Supplementary information, including the almanac (orbital parameters for the SVs), SV
health (P-code only) correlation of GPS time with UTC and other command and control
functions.
so how does it not give time(or SV clock time)and position of sattelites(almanac) i.e. D?