Data Acquisition and Processing
Some random time history data that might be of interest occur naturally in a digital format, for example, stock or commodity prices from one transaction to the next. In such cases, the data can be entered directly into a digital computer for analysis by the procedures detailed in Chapter 11. This chapter is concerned with those random data that represent continuous physical phenomena where specific data acquisition and processing procedures are required before an analysis of the data can be accomplished. The appropriate techniques for the acquisition and processing of continuous random data are heavily dependent on the physical phenomena represented by the data and the desired engineering goals of the processing. In broad terms, however, the required operations may be divided into four primary categories as follows:
Each of these categories involves sequential steps as schematically illustrated in Figure 10.1. The purpose of this chapter is to summarize the basic considerations associated with each of these key steps. The emphasis throughout is on potential sources of error beyond the statistical errors inherent in the data sampling considerations developed in Chapters 8 and 9. The digital computations required for the analysis of stationary and nonstationary random data through linear and nonlinear systems are covered in Chapters 11 through 14.