The table of facts for the various GNSSGNSS —Global Navigation Satellite System system is, unfortunately, one of those things that has to be learned.

NAVSTARGLONASSGLONASS —Global Orbiting Navigation Satellite System (Russia)GALILEO
Number of Satellites24 (3 Spare)24 (3 Spare)30 (6 Spare)
Number of Orbital Planes633
Angle to Equator55 degrees64.8 degrees56 degrees
Orbital Height (km)202001910023222
Orbital Height (nm)1098910313
Orbital Time (hrs)12:0011:1514:00
Earth ReferenceWGS84WGS84 —World Geodetic System 1984PZ-90ETRS89
L1 Frequency (MHz)1575.4216001164-1215
L2 Frequency1227.612001260-1300
L3 Frequency1559-1591
Time ReferenceAtomic ClockAtomic ClockRubidium/H2
Timing BasisGPSGPS —Global Positioning System (USA)/UTCUTC —Co-ordinated Universal TimeGLONASSGLONASS —Global Orbiting Navigation Satellite System (Russia)/UTCUTC —Co-ordinated Universal TimeGALILEO/UTCUTC —Co-ordinated Universal Time

Students have always reported when asked after exams that "pretty much all of it" came up on the exam. This is frustrating from both an instructor and student perspective as there is nothing inherently useful about any of the facts — even the frequencies are something you will never have to tune in yourself.

A good way to learn is to photograph the above table, save it as a tablet/mobile phone display, and then attempt to learn a little more each time you pick up the device. As ever with numbers, watch for the examiner giving incorrect units in the question or the answers (km instead of nm, GHz instead of MHz, etc.).

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How many satellites does the NAVSTAR GPSGPS —Global Positioning System (USA) GNSSGNSS —Global Navigation Satellite System constellation have?
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