| Popis: |
The paper deals with the problem of active sonar signal design for best range‐estimation accuracy at a time not necessarily coincident with the instant of measurement. Thus, velocity as well as range information, is important. For a single sonar ping a matrix of second‐order statistics of range and velocity errors is obtained for the case of ambient and/or reverberation noise interference. These error statistics are related to a generalized signal‐to‐noise ratio, and simple expressions are obtained for their relative magnitudes. For a particular type of linear FM signal it is shown that these relative magnitudes are independent of target or scatterer motion and of the relative importance of reverberation and ambient noise. The results are extended to the case of several sonar pings separated in time, and simple expressions are obtained for the over‐all error statistics. If two pings are to be used, it is shown that in many cases the first ping should be designed simply to measure target velocity, while th... |
