Echoview provides two impulse response filters. They are provided via the FIR filter and IIR filter operators respectively and implement the following algorithms:
The result for any given datapoint may be written as:
Result(0,d) = Operand(0,d)
Result(p,d) = C * Operand(p,d) + (1-C) * Operand(p-1,d) where p>0Where:
p identifies the ping
d identifies the datapoint (each ping contains a number of datapoints)
C is the coefficient entered on the FIR page of the Variable Properties dialog box.
Result(p,d) is the value of the datapoint d in ping p in the resulting variable.
Operand(p,d) is the value of the datapoint d in ping p in the operand variable.
Hence, if C = 1 the filter will make a copy of the operand variable, and if C = 0, the filter will make a copy of the operand variable shifted forward in time by one ping.
Note: This operation involves two pings, both from the operand variable. These pings must have matching ping geometry. If they do not there will be no resulting ping. See Using multiple operands for further information.
The result for any given datapoint may be written as:
Result(0,d) = Operand(0,d)
Result(p,d) = C * Operand(p,d) + (1-C) * Result(p-1,d) where p>0Where:
p identifies the ping
d identifies the datapoint (each ping contains a number of datapoints)
C is the coefficient entered on the IIR page of the Variable Properties dialog box.
Result(p,d) is the value of the datapoint d in ping p in the resulting variable.
Operand(p,d) is the value of the datapoint d in ping p in the operand variable.
Hence, if C = 1 the filter will make a copy of the operand variable, and if C = 0, the filter will make a copy of the operand variable with each ping containing the values of ping 0 from the operand variable.
Note: This operation involves two pings, one from the operand variable another from the result variable. These pings must have matching ping geometry. If they do not, there will be no resulting ping. See Using multiple operands for further information.