Category Archives: Radio Navigation

Radio Navigation

In the event of the re-use of Selective Availability, how does this affect, if at all, the navigation accuracy of the NAVSTAR/GPS satellite navigation system ?

A: It has no influence because, by selecting of the most suitable signals, the computing process in the receiver is quicker
B: It increases because only signals from satellites in the most suitable geometric constellation are selected by the receiver
C: It degrades position accuracy by manipulating satellite signals
D: It degrades accuracy by reducing the number of available satellites









Answer: C

The pencil shaped beam of an airborne weather radar is used in preference to the mapping mode for the determination of ground features:

A: beyond 150 NM because the wider beam gives better definition
B: beyond 100 NM because insufficient antenna tilt angle is available with the mapping mode
C: beyond 50 to 60 NM because more power can be concentrated in the narrower beam
D: when approaching coast-lines in polar regions









Answer: C