TABLE OF CONTENTS Many publications illustrate data management concepts with general examples from the world of accounting, finance, and human resources. While this is a good starting point, the range, complexity, and variability of geotechnical data make it a much more specialized area. This chapter introduces the most important types of geotechnical data, common data formats, and data specific to geoscience applications. Basic types of spatial (location), directional survey, depth-related, and time-related data are discussed in detail.
Geotechnical data include all information needed to accurately describe features within an earth model. In a fundamental sense, there are only two types of geotechnical data: spatial data and time-related data. Spatial data include all information that relates to relative and absolute position or location within the earth model. This definition encompasses latitude, longitude, and elevation for virtually any type of geoscience information. Time-related data include not only calendar and clock time but also absolute time in terms of geological age.
Virtually all geotechnical data is spatial in nature. That is, earth-related data can always be expressed in terms of a position on or under the earth's surface. However, the representation of that position (which is always a relative position) depends on the frame of reference and the projection system used to model the earth's curved surface.
The most common and widely applied reference system for positional data on the earth's surface is the latitude-longitude system of spatial coordinates. Latitude (the y value in a polar coordinate system) is...
