Welcome to AESS tutorial VII

We are pleased to offer Tutorial VII to members of the IEEE Aerospace and Electronic Systems Society. This is the seventh tutorial published by IEEE AESS. The first one was published in January 2004. It is a rare article from which nothing is to be learned. What do we mean by tutorial? According to Peter Willett, our Vice President of Publications, "there are two kinds of tutorial articles. Those that provide a primer on an established topic, and those that let us in on the ground floor of something of emerging importance." In both cases, our authors are for the most part noted experts willing to share their knowledge and experience in a written field guide.