© Valeport Limited 2003
MIDAS Surveyor Operating Manual
Page 21
0420805d.doc
4.2.7.1
Defaults
The default spheroid is WGS84, and the default grid is UTM. If any of the defining parameters for the spheroid or grid
have been altered, the default settings can be restored as follows:
•
Highlight the WGS84 default or UTM default function in the sub menu as required, and use the arrow keys to scroll
to “DATUM = WGS84” or “grid/proj = UTM” to revert to default settings. Again, use Enter to confirm.
When using a UTM projection, the user may also set the position of the Central Meridian Zone – by default this is 3°, but
may be changed in 6° steps up or down. Whether the system is being operated in the North or South Hemisphere may
also be defined.
•
To alter the UTM CM zone, use the arrow keys to move the centre of the grid in 6° steps, using Enter to confirm.
•
To alter the Hemisphere, use the up or down key to toggle between North and South, again using Enter to confirm.
4.2.7.2
Changing Grid and Spheroid Parameters
All the parameters for setting up the spheroid and local grid as detailed above are to be found in the Geodetic Setup sub
menu. However, the method for changing these large numbers is different to that thus far encountered; it would take a
long time to scroll up or down to the required value. The method described below applies to all of the parameters
detailed above:
•
To alter the desired parameter, press the Enter key.
•
An arrow will appear under the leading digit of the number. Use the up and down keys to alter this digit as required.
The digit will scroll from 0 through to 9, followed by a “–“ sign, a “.” and finally a space.
•
When the digit has been correctly set, use the right arrow key to move to the next digit and repeat the process.
•
When the full number is displayed on screen as required, press the Enter key.
4.2.8
ECHOSOUNDER SETUP
The MIDAS Surveyor incorporates Valeport’s own echosounder, which is able to operate as either a single or dual
channel system. As standard, the MIDAS Surveyor is supplied with a single 210kHz analogue transducer, but an
additional 33kHz transducer may be supplied as well. Alternatively a single combined 210/33kHz transducer may be
supplied.
4.2.8.1
Internal/External Echosounder
The MIDAS Surveyor may use either its integral echosounder and transducer or a depth input from an external digital
device. Alternatively, depth sounding may be disabled entirely.
Use the arrow keys to toggle between internal echosounder, external echosounder, or disabled, and Enter to confirm.
