Analytical Tools

In addition to providing the user with easy control and access to the experiment, the GUI also provides a number of tools used for graphical analysis. The graphical tools utilized several features in MATLAB and are listed below.

• Time domain plot of signal
• Spectrogram
• Periodocgram
• Position Estimation plot

These tools proved to be the most usefull aspect of the experiment. Through the use of the built in functions, the user is able to easily view the signal, power spectrum, spectral content, and estimated location of source. The ability to do use these tools on each individual channel allowed us to explore a great deal of different methods and ideas in a rapid fashion. The source estimation location plots came in two varieties. The first is the simple plot of actual source and estimated source in reference to the array. The other is the plot of the same thing made with the additional feature of adding in all of the possible points the array was able to determine based on the specified parameters. This feature is detailed further in the observations section of this site. It was this observation that finally made the experiemnt possible so it will be discussed in detail later. Also, the spectral content plots were especially helpfull in finding what frequency the noise was found in. As it turned out, the noise in most of the rooms that the experiemnt was conducted in was around 600 Hz due to the AC of the building. By locating this noise, we were able to later filter it out to improve the accuracy of our experiment. Below are several examples of the graphical tools mentioned above.