This book is based on a course given at the University of Chicago in 1980-81. As with the course, the main motivation of this work is to present an accessible treatment, assuming minimal background, of the profound work of G. A. Margulis concerning rigidity, arithmeticity, and structure of lattices in semi simple groups, and related work of the author on the actions of semisimple groups and their lattice subgroups. In doing so, we develop the necessary prerequisites from earlier work of Borel, Furstenberg, Kazhdan, Moore, and others. One of the difficulties involved in an exposition of this material is the continuous interplay between ideas from the theory of algebraic groups on the one hand and ergodic theory on the other. This, of course, is not so much a mathematical difficulty as a cultural one, as the number of persons comfortable in both areas has not traditionally been large. We hope this work will also serve as a contribution towards improving that situation. While there are a number of satisfactory introductory expositions of the ergodic theory of integer or real line actions, there is no such exposition of the type of ergodic theoretic results with which we shall be dealing (concerning actions of more general groups), and hence we have assumed absolutely no knowledge of ergodic theory (not even the definition of "ergodic") on the part of the reader. All results are developed in full detail."

The GCDB Handbook for GIS is a quick reference to the practical applications of the Bureau of Land Management's Geographic Coordinate Database for Geographic Information System users and land surveyors. Because the GCDB is important to GIS in the Public Lands Survey states, GIS users and land surveyors should understand what the GCDB is and how the GCDB affects GIS data alignment and spatial accuracy, and should know how to use the GCDB for a number of GIS and surveying tasks.

The GIS for Surveyors book explains how surveyors use Geographic Information Systems (GIS) technologies to support land surveying activities and how GIS helps surveyors work more effectively and efficiently. Additionally, the book covers how surveyors support GIS data development, integrity, and spatial accuracy. GIS concepts, overviews, and specific examples are presented on a variety of topics related to Geographic Information Systems relevant to land surveying. The book also addresses important issues and helpful applications. Major topics covered are GIS fundamentals, data sources, using GIS in the survey office, using GIS in the field, surveying for GIS, and spatial accuracy considerations.