WV
u
u
=
+
1
2
2
2
WD
′ =
arctan
u
u
2
1
with
0
90
° ≤
′ ≤
°
WD
As
u
1
and
u
2
may also be relative and arctan is only defined for a
range 0°...90°, the true direction angle
WD
is determined by fol-
lowing table:
u
1
+
-
-
+
u
2
+
+
-
-
WD
′
WD
′
180
° −
′
WD 180
° +
′
WD 360
° −
′
WD
For
u
1
0
=
,
WD
= °
0
is defined.
Hardware Manual COMBILOG 1022
171
