Pregledni rad
Beginnings of Satellite Navigation
Miljenko Solarić
; Geodetski fakultet Sveučilišta u Zagrebu, Zagreb, Hrvatska
Sažetak
The first satellite navigation system called
the Navy Navigation Satellite System (NNSS) or
TRANSIT was planned in the USA in 1958. It consisted
of 5-6 artificial Earth satellites, was set in motion
for the USA military in 1964, and in 1967 for civilian
purposes. The frequency shift of received radio waves
emitted from the satellite and caused by the Doppler
effect was measured. The TRANSIT satellite speed of
approaching or moving away was derived from that;
the TRANSIT satellites emmited also their own coordinates.
Then the ship's position was determined by
an intersection of three hyperboloids, which were determined
from differences of distances in three time
intervals. Maintenance of this navigation system was
stopped in 1996, but it is still being used in the USA
Navy for exploring the ionosphere.
Furthermore, results of Doppler measurements in international
projects at the Hvar Observatory from 1982
and 1983. This was the first time in Croatia and the
former country that the coordinates of the Hvar Observatory
were determined in the unique world coordinate
system WGS'72.
The paper ends with a brief representation of the Tsiklon
Doppler navigation system produced in the former
Soviet Union, and there is a list of some of numerous
produced and designed satellite navigation systems.
Ključne riječi
navigation; satellites; radio wave; broadcast ephemeris; precise ephemeris; Doppler shift of frequencies; determination position of ship; Navy Navigational Satellite System (NNSS)
Hrčak ID:
27005
URI
Datum izdavanja:
30.6.2008.
Posjeta: 2.603 *