PL-573
AiRanger SPL
Page 87
Technical Refer
e
nce
Technical Reference
Transmit Pulse
The SPL transmit pulse consists of one or more electrical "shot" pulses, which are
supplied to a transducer connected to the SPL 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
(removing noise, P821 and P822) and
reforming
(connecting fragmented echo peaks, P823) the
echo profile
(digitized
signal representing the echo signal received).
True echo selection is achieved by establishing the criteria which a portion of the
echo profile must meet to be considered the
true echo
(echo reflected by the
intended target).
Insignificant portions of the echo profile outside of the measurement range (Span
P007 + Range Extension P801), below the TVT Curve (P830 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(s)
(P820) and Short Shot Bias (P850) programmed. When a combination of Algorithms
are used, the portion of the Echo Profile providing the best averaged Echo
Confidence (P805), is selected as the true echo.
True echo verification is automatically achieved by comparing the position (relation in
time after transmit) of the "new" echo to the previously accepted echo position.
If the new echo is within the Echo Lock Window (P713), the new echo is accepted
and displays, outputs, and relays are updated as restricted by the Fuzz Filter (P710)
and Rate Parameters (P700 to P703). If the new echo is outside of the Echo Lock
Window, the new echo is not accepted until
Echo Lock
(measurement repeatability,
P711) requirements are satisfied.
Summary of Contents for AiRanger SPL PL-573
Page 1: ...AIRANGER SPL Instruction Manual PL 573 March 2001 IRANGER SPL 33455730 Rev 1 2 ...
Page 8: ...Page 8 AiRanger SPL PL 573 Specifications ...
Page 24: ...Page 24 AiRanger SPL PL 573 Installation ...
Page 86: ...Page 86 AiRanger SPL PL 573 Enhancement Param ...
Page 102: ...Page 102 AiRanger SPL PL 573 Maintenance ...
Page 108: ...Page 108 AiRanger SPL PL 573 Troubleshooting ...