March Air Reserve Base Identification and Characterization of Obstructions to Flight

Publication Date


Committee Chair

Mark P. Kumler, Ph.D.

Committee Members

Lee H. Peterson, M.S.
Barbara L. Willsey, M.A., U.S. Naval War College
Robert J. Nelson, Chief, NGA Geodetic Surveys Division


The identification and characterization of obstructions to flight is an important aspect of the responsibilities of airfield Terminal Instrument Procedures (TERPS) specialists. The purpose of this Major Individual Project (MIP) is to develop a GIS-based obstruction identification tool for the TERPS specialist at March Air Reserve Base (ARB) that will enable him to more effectively address that responsibility.

The tool developed through the completion of this MIP accurately identifies the obstructions in the vicinity of the March ARB. Its imagery and elevation layers provide a snapshot of characteristics in the area as of late 2004. Unfortunately, more recent changes in the area, e.g. new water towers or radio masts, are not reflected. This prototype overcomes this limitation by allowing TERPS specialists to accurately characterize the effect these types of changes have on airspace operations. The specialist has the option of either locating the area in question on high resolution imagery or by locating that area on the map by its coordinates. By “clicking” on the map, accurate ground elevation values are displayed. Given a tower’s height above ground via construction diagrams, the degree of its intrusion into airspace can then be determined.

Detailed within this publication is the process necessary to create similar products at other airfields. Critical to this methodology is the use of LIDAR, high resolution imagery, and accurate ground truth data. An in-depth analysis of the accuracies of the elevation and imagery data is implicit in the development of this tool, and is included within this document.

The utility of this Obstruction Identification Tool has been proven through its use twice in 2005. In the first case an accurate ground elevation was determined at the construction site for a new tower adjacent to March ARB. In the second case, the ground elevation of a new navigational aide placed along the runway centerline was determined. NGA publications detailing the findings were forwarded to the TERPS specialist, resulting in the significant enhancement of airfield flight procedures.

Full text is available at the University of Redlands


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