David F. Mezera Associate Professor, Retired Address/E-mail Program Affiliations Education Fields of Interest Awards & Honors Summary

Contact Information

1214 Engineering Hall 1415 Engineering Drive Madison, WI 53706

Tel: 608/262-4365 E-mail: mezera@engr.wisc.edu

Program Affiliations

• Civil and Environmental Engineering

Education

• B.S., University of Wisconsin-Madison
• M.S., University of Wisconsin-Madison
• Ph.D., University of Wisconsin-Madison

Fields of Interest

• spatial control network adjustments
• satellite geopositioning
• engineering and geodetic control surveying
• geospatial information engineering
• land information systems.

Selected Awards, Honors and Societies

• American Geophysical Union
• American Society of Civil Engineers
• American Society for Engineering Education
• American Society of Photogrammetry and Remote Sensing
• Urban & Regional Information Systems Association
• Wisconsin Land Information Association
• Wisconsin Society of Land Surveyors

Summary

My students and I, depending on their particular interests, work in two broad and related research areas: engineering and geodetic control networks; and geospatial information engineering/land information systems (LIS).

Past studies have involved various aspects of alternative geopositioning methods. We have conducted geodetic control densification surveys by conventional methods, by doppler satellite translocation, by inertial system traverse, and by Global Positioning System (GPS) satellite methods. Three- dimensional geodetic adjustment techniques for local control networks have been studied as an alternative to separate "horizontal" and "vertical" networks. Cost models have been developed for alternative geopositioning methods to support planning and cost estimating for proposed densifications. We have refined weighting methods to better account for systematic and random error effects in precise leveling network adjustments.

We continue working to develop of reliable methods for deriving orthometric heights (elevations) from ellipsoidal heights obtained by GPS surveying. GPS and precise differential leveling have been used to produce geoid heights which provide a basis for more refined geoid modeling. The combination of gravity observations with the GPS and leveling data is also being evaluated as a possible solution for economical development of local geoid models with sufficient accuracy to support engineering applications. Our research has included the use of GIS (Geographic Information System) software to analyze and optimize the geometry of the GPS satellite constellation. We are studying atmospheric refraction effects on Total Station instrument observations with a goal of developing, for engineering control aplications, reliable trigonometric leveling and three- dimensional network adjustment methods. And we are also working on an adjustment model for combining airborne kinematic GPS data with terrestrial observations, and determining effective combinations of such data for photogrammetric mapping applications.

Interdisciplinary teams of our faculty and students have conducted research on development and implementation of LIS. A primary objective was to evaluate prototype parcel-based land information systems for use at the local government level. Our work included: consideration of the spatial control frameworks required to provide compatibility; evaluation of existing maps and land records as input data sources; and characterization of the reliability of boundaries created by combining several overlays. Our LIS/GIS-related work has continued with research involving: the basic nature of digitization errors inherent in converting graphic data sources into digital format; and a technique for characterizing the temporal aspects of GIS databases.