Plain English Meaning

When you turn the GPS on, it checks itself, confirms its data is good, and finds enough satellites to know where it is — only then is it ready to navigate.

Full Definition

The startup sequence a GPS receiver performs when powered on, in which it runs internal self-checks on its hardware and software, confirms the database is valid, and then acquires satellite signals to establish a current position before being used for navigation.

Context Anchor

Seen during GPS start-up, before using the navigator for route guidance, approaches, or position awareness.

Derivation

Test' refers to the 's built-in self-tests of its electronics and software. 'Initialization' comes from Latin 'initium' meaning 'beginning' — setting the unit to a known starting , including a current position and a valid , before it can be trusted for .