EOD signal measurement and ideal dipole approximation.

<p><b>A</b>) Our experimental setup. Electrodes were attached on the tank wall, and concurrent video recordings were made under infrared illumination. <b>B</b>) Received signal intensity (RSI) measurement. The original waveforms (green) were rectified then summed from all channels (blue). Signal envelope (red curve) was extracted using an RMS filter, and a pulse timing reference (thick grey) was determined at the peak. An instantaneous slope of the original waveform was measured at 250 µsec before the reference timing (red line). <b>C</b>) Ideal dipole voltage (<i>V_dip</i>) approximation of an electric fish in two dimensions. <b>D</b>) Lookup table search using a dot-product to find the best matching vector.