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.
Examples of the three image quality groups; a, b show a good quality image and a medium quality image respectively. c, d are two low quality images; c has blurred shadows and a seaming artifact, while d shows some struts having only clear shadow without bright spot
