Simrad CA34, Руководство пользователя

Страница: 191 / 212

CA34/44/54 Glossary of terms Appendix A-3
V
elocity – speed towards approaching waypoint.
XTE
– Cross-Track-Error (-Distance), measured magnitude of the position
error perpendicular to the intended track line.
Echosounder section:
Alarms – can be set to sound a “beep” if the echosounder detects a target
above (shallower than) a minimum alarm depth or below (deeper than) a
maximum alarm depth. The CAXX allows you to set the alarm depths and to
enable or disable both the minimum and maximum depth alarms.
A-scope
– a method of displaying the echosounder information. In A-Scope
mode, the echoes are displayed in a “bar-graph” format, with stronger echoes
displayed not only in the color representing their target strength, but also in a
width representing their target strength.
Depths
– DK = Depth below keel, DS = Depth below surface, DT = Depth
below transducer.
Echogram background color
– is the color shown on the CAXX in the event
no target is present. There are three colors to choose from, white, blue or
black, where black is especially useful during nighttime operation when the
white background could appear too bright.
Echosounder frequency 38 (CA44/54), 50 or 200 kHz can be selected to suit
the task. 200 kHz is for general purpose and offers optimum discrimination
and a narrow transmitter beam. 38/50 kHz is for searching in a wider area,
determining bottom conditions and going the deepest.
Transducer
– the transducer serves as the acoustic “loudspeaker” and “micro-
phone” to send and receive the signals through the water. They are most
often made from ceramic elements carefully built into a robust housing. The
ceramic elements change shape when a voltage is applied across them (when
the CAXX transmits a signal), and they also generate a voltage when they
encounter sound waves (as when the CAXX is receiving an echo).
Radar section:
Cursor function – The cursor appears on the display as a small symbol.
To activate the cursor, just press the cursor key. The cursor may now be
positioned by using the cursor key. When the cursor is set to a position on the