Q 01/05

What do the letters GPS stand for?

A) Global Positioning Satellite

B) Global Positioning System

C) Geographic Positioning System

D) Global Pathfinding Service

Answer · why

B) Global Positioning System

Global Positioning System, not 'Satellite': the satellites are only one of three parts, alongside the ground stations that steer them and the receiver...

Q 02/05

Which treasure-hunting hobby was born in May 2000, days after civilian GPS signals suddenly became far more accurate?

A) Orienteering

B) Letterboxing

C) Geocaching

D) Metal detecting

Answer · why

C) Geocaching

Geocaching: on 3 May 2000 Dave Ulmer hid a bucket of trinkets in the woods of Oregon and posted its coordinates online. Within three days, two strange...

Q 03/05

Which branch of the US military operates the GPS satellites?

A) The Navy

B) The Air Force

C) The Marine Corps

D) The Space Force

Answer · why

D) The Space Force

The Space Force, founded in 2019, took GPS over from the Air Force. US law obliges the Pentagon to keep the civilian signal on worldwide, free of any ...

Q 04/05

What does every GPS satellite broadcast?

A) Street maps

B) Compass bearings

C) Driving directions

D) Its position and time

Answer · why

D) Its position and time

Its position and time: a receiver works out where it is from how long each signal took to arrive. Because receivers only listen and never transmit, an...

Q 05/05

A GPS fix needs a fourth satellite to correct an error in the receiver's what?

A) Clock

B) Compass

C) Antenna

D) Gyroscope

Answer · why

A) Clock

Clock: the cheap clock in a phone drifts, and light covers about 300 metres in a millionth of a second, so a tiny timing slip would wreck the fix.