Phrase " nap-of-the-earth" origins

Posted by Burt on January 26, 2003

Nap of the earth, as a military phrase refers to low level contoured fight over the earth surface.
A friend contends that the phrase is older than it usage in the Vietnam war era, usauly pretaining to helicopter tactics.
Have been unable to find the origin of this phrase, and would welcome any help. E-mails welcome.