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.
Day 1 (black, x-direction: open circle, y-direction: filled circle) and day 2 (green, x-direction: open square, y-direction: filled square) show little deviation from one another. Before measurement on day 3 (magenta, x-direction: open triangle, y-direction: filled triangle), the system’s cylindrical lens was removed and replaced.
