TABLE OF CONTENTS 'There are three kinds of lies - lies, damned lies, and statistics.'
Benjamin Disraeli
Signal processing leading to target detection was discussed in general terms in Chapter 3, Section 3.6. We now quantify the detection process. Appendix A2 expands on some matters of detail. This chapter, which owes much to expert guidance from Professor E. D. R. Shearman, enables P D to be predicted. Although long, we will only scratch the surface of detection theory. For a taster of the extensive mathematics necessary for rigorous treatment, see for example, Rohan [1], Chapter 3. Theoretical work is ongoing, driven by the needs of telecommunications, and is leading to introduction of refinements in radar data handling software. The next chapter will discuss the errors in measurement and calculation arising from the uncertainties surrounding radar operation.
Historically, detection was the machine process of extracting radio signals from the carrier, originally using a coherer on the incoming Morse-modulated RF carrier and later by diode rectification or 'demodulation' of the IF. The operator then mentally extracted the Morse or speech data from the residual noise and interference, although machine Morse inkers were soon developed. The rectification process came to be called detection. Radar and radio receivers are similar in some ways, but we use detection in a wider sense, to embrace the whole task of extracting the presence of a target from the surrounding noise and clutter. Demodulation of the IF is one stage of the...
