Field
Option
Description
•
For
Method:
Two WGS84 points
: The
rotation of the transformation calculated
as required azimuth minus azimuth. The
field is updated as
Point 1
,
Point 2
and
Required azimuth
are changed.
Editable field
•
For
Method:
User entered
: To manually
type in the orientation of the transfor-
mation or to calculated in
Compute
Reqrd Azimuth
.
Coordinate
system
Selectable list Coordinate system to provide the direction of
grid North in the area where the control
point used for determining the local coordi-
nate system, is located. Available for
Method:
Convergence angle
.
WGS84
point
Selectable list WGS 1984 point of which the convergence
angle is calculated. Available for
Method:
Convergence angle
.
Point 1
Selectable list First point to use for computation of
Azi-
muth
. Available for
Method:
Two WGS84
points
.
Point 2
Selectable list Second point to use for computation of
Azi-
muth
. Available for
Method:
Two WGS84
points
.
Azimuth
Display only
Computed azimuth between
Point 1
and
Point 2
. Available for
Method:
Two WGS84
points
.
Required
azimuth
Editable field
The required grid azimuth, computed
between two local points. Refer to "39.4.2
Computing Required Azimuth". Available for
Method:
Two WGS84 points
.
Diagram for Onestep, Method: Convergence angle
a
c
d
b
f
e
SYS13_008
a
WGS 1984 coordinate system
b
Local coordinate system
c
Geodetic North
d
Grid North
e
Point on WGS 1984 datum
f
Meridian
α
Convergence angle
548
Determine Coordinate System
