Reson Seabat 8101

System Operation3.4.3 TxPwrThis menu selection allows the operator to increase, or decrease, the amount ofpower (acoustic energy) transmitted into the water. The selections are OFF, andpower settings of OFF, 1 through 7, and FULL. Each increment is approximately3dB. FULL yields a Source Level of approximately 210dB re 1µPa @ 1m with thestandard stick projector. The optional Extended Range (ER) projector, the level 8output power increases to 220dB re 1µPa @ 1m.3.4.4 TxPulseThe transmit pulse width selection allows the operator to change the pulse widthof the transmitted signal. For a given power setting, the narrower the pulse width,the higher the degree of resolution that can be obtained; but the range capabilitywill suffer. A longer pulse width increases the average power of the transmitpulse and increases the range but decreases the resolution.The pulse widths available are from 21µs to 225µs in increments of approximately4µs. A pulse width of 75µs is typical for most applications. The minimumrecommended pulse width is 33µs.3.4.5 RxGainThis menu item allows the operator to select the amount of receiver gain appliedto the returned sonar signal. RxGain has two independent settings; TVG andFIXED. TVG has a range of 1 to 45 in 1dB steps while FIXED gain is a nonlinearscale.3.4.6 GainModeThe gain mode menu selection provides the operator with a the ability to applydifferent type of gain to the received signal. The gain modes available are:FIXED:TVG:This mode applies a fixed (does not vary with time) gain to the returnedsignal. It is normally only used for very short range operation(less than 10 meters).The Time Varied Gain mode applies a variable gain to the returnedsignal, based upon the formula:Receiver gain = 2 α R + Sp log R + GWhere:α = Absorption loss in dB/kmR = Range in metersSp = Spreading loss coefficientG = Receiver gain______________________________________________________________________SeaBat 8101 Operator's Manual 3-6 Version 3.02