Figure 4.
Illustrations of two-dimensional sampling schemes A. Regular sampling scheme B. Truncated sampling scheme (10% of regular sampling scheme) C. NUS scheme (33% of truncated sampling scheme).
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.