Point Calculation - Sokkia im-101 Operator's Manual

6. Press [OK] in the screen shown in step 5 to calculate the
center peg coordinates. The coordinates are then displayed
in this screen.
7. Press {ESC} three times to finish Parabola calculation and
return to <Road>.

• ECC-ETC curve length/ECC stationing chainage/Q stationing chainage (Set out pt sta) input range: 0.000 to
99999.999 (m)

25.6 3 Point Calculation

The coordinates of a cardinal point, an arbitrary centerline peg, and width pegs can be found from the
coordinates of 3 IP points and curve properties.
It is then possible to proceed with the setting-out of the cardinal point, arbitrary center peg, and width pegs
P2
KE1
KA1
A1
DL
BL
P1
Offset
• When parameter A1, parameter A2 and radius R have all been input a clothoid is created and the KA1, KE1,
KE2 and KA2 points can be found.
• When parameter A1 and parameter A2 have been input and radius R is "Null", a clothoid without a transition
curve is created and the KA1, KE1, and KA2 points can be found.
• When parameter A1 and parameter A2 are both "Null" and only radius R has been input, a circular curve is
created and the BC point and EC point can be found.
PROCEDURE
1. In the second page of the OBS mode screen, press
[MENU], then select "Road".
2. Select "3PT Curve" to enter the 3 point calculation menu.
Parameters input:
KE2
KA2
R
A2
Q
P3
P a r a b o l a / C L p e g
N
E
A z m t h
WIDTH
BP point (P1)
IP point (P2)
EP point (P3)
Intersection angle
Direction of curve
BP-IP length
IP-EP length
Clothoid parameter A1
Clothoid parameter A2
Curve radius (R)
Route width (BL)
Route width (BL)
Stationing to CL peg (DL)
3 P T C u r v e
I P & Ta n
A l i g n m e n t
E D M
130
25. ROUTE SURVEYING
4 7 5 0 9 0 . 3 1 1
2 0 3 9 0 5 . 1 8 6
2 6 5 8 ' 2 6 "
REC S-O CENTER