Appendix B: Technical Reference; Transmit Pulse; Echo Processing - Siemens HydroRanger 200 Instruction Manual

Appendix B: Technical Reference

Transmit Pulse

The transmit pulse consists of one or more electrical "shot" pulses, which are supplied to
the transducer connected to the HydroRanger 200 terminals. The transducer fires an
acoustic "shot" for each electrical pulse supplied. After each shot is fired, sufficient time
is provided for echo (shot reflection) reception before the next (if applicable) shot is fired.
After all shots of the transmit pulse are fired, the resultant echoes are processed. The
transmit pulse shot number, frequency, duration, delay, and associated measurement
range are defined by parameters P803 and P840 to P852.

Echo Processing

Echo processing consists of echo enhancement, true echo selection, and selected echo
verification.
Echo Enhancement is achieved by filtering (P821 and P822) and reforming (P823) the echo
profile. The true echo (echo reflected by the intended target) is selected when that
portion of the echo profile meets the evaluation criteria of Sonic Intelligence®.
Insignificant portions of the echo profile outside of the measurement range (Span P006 +
Range Extension P801), below the TVT Curve (P830, and P832 to P835), and less than the
Confidence Threshold (P804) and Short Shot Floor (P851) are automatically disregarded.
The remaining portions of the Echo Profile are evaluated using the Algorithm (P820) and
Short Shot Bias (P850). The Echo Profile portion providing the best Echo Confidence
(P805) is selected.
True echo verification is automatic. The position (relation in time after transmit) of the
new echo is compared to that of the previously accepted echo. When the new echo is
within the Echo Lock Window (P713), it is accepted and displays, outputs, and relays are
updated per the Fuzz Filter (P710) and Rate Parameters (P700 to P703). If the new echo is
outside of the Window, it is not accepted until Echo Lock (P711) requirements are
satisfied.
Dolphin Plus Display
Cursor
Echo Marker
TVT Curve
Echo Profile
Page 224 HydroRanger 200 – INSTRUCTION MANUAL 7ML19985FC03