A simple relationship between frequency and range averages for broadband sonar

All sonars have a bandwidth, and often the assumption of single frequency propagation will mislead the sonar designer. It is shown here theoretically, and by demonstration using SAFARI, that a frequency average can often be approximated closely by a variable width running range average in which the width or window size is proportional to range. In fact if the bandwidth is expressed as a fraction α of the center frequency one should use a range averaging width of α times the range. The limitations of such a scheme are also addressed.