True wind correction |
This is
a calibration that
adds or subtracts from the magnitude of the true wind angle. If the
true wind angle is too narrow (too small in magnigude), wind direction
will head when you tack. If it’s too wide (too large in
magnitude), you will be lifted when you tack. QuikCal adds or subtracts
an adjustable number of degrees from the magnitude of the true wind
angle; for a positive 2.0 QuikCal, 21 degrees becomes 23, and
–21
degrees becomes -23. |
Cal Boatspeed Master &
Offset |
The
overall calibration
of Boatspeed is set by the interface
signature switch and the CAL Boatspeed Master or the
K1 command or AutoCal. If a heel is available, Boatspeed is modulated
by heel and
CAL Boatspeed Offset. |
Cal
Leeway |
This
calibration is the
factor used in calculation of leeway angle (See Leeway function). The
leeway calibration is set to zero when shipped from the factory, so the
leeway will always be zero until you are ready for it. Since leeway and
upwash are compensating errors in true wind angle, you should go about
adjusting both of these functions at the same time. |
Cal
Windangle Offset |
Zeros
the apparent wind angle. A
value of 1.0 makes windangle apparent 1 degree narrower on starboard
and 1
degree wider on port. A value of -1.0 does the opposite. |
Cal Windspeed |
Changes
the apparent wind speed.
K1=1.00 is 100% of the nominal calibration of the signature switch
calibration.
K5=0.99 lowers windspeed apparent 1%, while K5=1.01 raises it 1%. |
Cal
Upwash & Upwash Slope |
The wind
is bent by the
sails as it approaches them. In fact, the drive created by the sails is
caused by this bending. However, if the masthead is inside this
disturbed flow, it is not reading the proper angle and speed. This
effect is termed upwash and is a complicated concept to understand.
Upwash broadens (>0) or narrows(<0) the apparent wind
angle
upwind. Since apparent wind angle has a 3:1 effect on true wind angle
(and therefore wind direction) upwind, Upwash is the calibration to use
to set upwind wind direction.
Upwash slope is a calibration number that changes Upwash with True
Windspeed. The complete Upwash function is |
Leeway |
(tag
'l') is the
angle between the ship's heading and the
boatspeed resulting from side pressure by the sails,
resisted by the keel. It is used in true wind and dead-reckoning
calculations, and is displayed as an aid to proper calibration. Leeway
is calculated from heel angle, boatspeed and Leeway Cal. |