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25. ROUTE SURVEYING
The coordinates of the center peg and width pegs on a circular curve can be found from the coordinates of the
BC point and IP point.
It is then possible to proceed with the setting-out of the center peg and width pegs.
PROCEDURE
1. In the second page of the OBS mode screen, press
[MENU]
, then select "Road".
2. Select "Circ.Curve" to enter the Circular Curve menu.
3. Input the coordinates of the BC point (reference point), then
press
[OK]
.
4. Input the coordinates of the IP point, then press
[OK]
.
• The azimuth angle to the IP point can be set by pressing
[AZMTH]
on the second page. Press
[COORD]
to return to
coordinate input.
5. Enter the curve direction, curve radius, offset, and follow-up
distance.
6. Press
[OK]
in the screen shown in step 5 to calculate the
center peg coordinates. The coordinates and azimuth angle
are then displayed in this screen.
25.3 Circular Curve Calculation
BC point (P1)
IP point (P2)
Circular curve radius (R)
Follow-up distance (DL)
Route width (BL)
Target point (Q)
Width peg (QR, QL)
BL-
BL
Q
QL
QR
AZ
P2
R
DL
Offset
Route origin
P1
DL Offset
R o a d
O c c . O r i e n .
L i n e
C i r c . C u r v e
S p i r a l
P a r a b o l a
C i r c . C u r v e / C L p e g
S t . o f s
S t a . . i n g
0 . 0 0 0 m
9 0 . 0 0 0 m
D i r e c t . R i g h t
R a d i u s
8 5 . 0 0 0
m
OK
N
E
6 5 . 7 7 9
C i r c . C u r v e / C L p e g
1 7 8 . 7 3 9
A z m t h
0 0 0 0 ' 0 0 "
WIDTH
CENTER
REC
S-O