Definition
A ground-based receiver, located at or near a navigation facility, that continuously samples the signal being transmitted and alerts the facility (or shuts it down) if the signal drifts out of tolerance.
Plain English
A device on the ground that constantly listens to a navigation transmitter to make sure it is still sending a correct, usable signal. If the signal goes bad, the system warns controllers or removes the facility from service.
Context Anchor
Seen in discussions of how ground-based navigation facilities are monitored for proper operation.
Derivation
Sampling' here means taking small, repeated checks of something to judge the whole. The receiver doesn't use the signal to navigate — it samples the signal to verify quality.
Why Pilots Care
It ensures navigation signals remain accurate so pilots can rely on them without risk of undetected errors during instrument flight.
Intuition Check
Do not read “receiver” here as the radio receiver in the aircraft. A signal-sampling receiver is part of the monitoring system for the ground facility.
Example Sentence 1
If the signal-sampling receiver detects that the localizer is transmitting outside tolerance, the facility is automatically removed from service.
Example Sentence 2
Technicians review data from the signal-sampling receiver during routine checks to confirm the localizer meets FAA tolerances.