Often there are some advantages in using frequency domain techniques, as opposed to using strictly time domain techniques, to analyze signals obtained in data acquisition. The merits and possible issues of using a particular frequency-based transform methodology along with subsequent graphical analyses are discussed. Appropriate choices for analyzing signals in the frequency domain can often improve the overall system during the concept, development, and/or testing phase of many data acquisition systems.Frequency domain analysis plays an important role in the design and testing of many militarized systems, including wireless communications, remote sensing, radar processing, audio processing (such as speech recognition/authentication, watermarking, and compression/VoIP), and more. The development process of an embedded computing military application often requires sampling real-world physical systems through a data acquisition process that results in a digital representation of those signals.
Although the data representing these signals is most often sampled in the time domain, many applications engineers find it easier – and more conceptually clear – to work with the data in the frequency domain. This is because of the many engineering relationships governing information, which are typically described in the frequency domain. A thorough frequency analysis of the data being acquired and processed can facilitate the retrieval of subtle information contained within the signal and provide valuable insight into the real-world environment that will be encountered. Often that subtle information includes signal artifacts with very low Signal-to-Noise Ratios (SNRs), which might be missed in analyzing the data exclusively from the time domain.[Continue reading →]