Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Black line: Mean of the pick-up signal, red line: maximum pick-up signal and blue line minimum pick-up signal. Dashed lines: 95% coefficient interval of maximum and minimum pick-up signal.
