2. RECOGNITION OF GEOGRAPHICAL 
SPACE INFORMATION AND TOPOGRAPHY 
The geographic space information includes the 
points to be positively selected as sites of transmis- 
sion line (Positive Control Point; PCP) and those con- 
sidered not suitable for passage of the lines (Negative 
Control Point; NCP) as well as the areas to be selected. 
Figure 2 gives an example of these respective fac- 
tors. PCP are line start/terminal points and interme- 
diate fixed points, while NCP includes the points that 
do not allow the construction of tower nor passage of 
line and those that allow only the passage. 
The present system incorporates these judgment 
codes into the grid data. From the topographic view- 
points it is recommended to select such locations as 
Stable mountaintops, crest lines and slopes that allow 
to have a distance of electric wire from ground (a 
certain restriction existing for the clearance be- 
tween the wire and the ground) and reduce the height of 
the tower. 
This system has therefore developed and adopted 
a method to evaluate the locations of towers classify- 
ing the topographic patterns by elevation data of the 
grids. The method consists in classifying the to- 
pography into 15 groups by the ratios and combinations 
of the collection vector (C) and deluge vector (D) 
which can be obtained from the differential elevation 
of given points with the Surrounding grid inter- 
Sections. (See Figure 3). 
It is so designed that suitable topographic geome- 
try can be selected in response to the Steepness of 
Slope and distribution of the subject areas by assign- 
ing the code number and the maximum gradient when simu- 
lating. Figure 4 shows up an exemplary distribution at 
a selectable point. 
  
  
  
Natural Conditions: 
Crumbling Land, Steep Mountainous Areas, Faults, 
Streams, Lakes and Marshes, Damp Ground, etc. 
P ne s EE 74 
a ns dA IL 
AE 
Towns/Villages, Establishments/Facilities, 
Temples and Shrines, Communication Facilities 
and Sightseeing Areas 
     
     
   
          
Social and Living 
Environmental Conditions: 
  
Rules and Regulations: 
National Parks, Planned Areas 
and Environmental Protection Areas 
  
  
Figure 2 Classification of Restrictions (NCP) 
884 
  
Topographic attern t E 
Code pograp P Geometric Sectional 
No. | Classi- |Sub-clas- | shape in geometry 
fication | sification| drawing 
  
Remarks 
  
  
Gradient 
Moun- ; 
14 tain Summit > < 55° 
top 
13 Ridge ONS 
A 
12 Saddle D = 
SE 
Convex Convex Gradient 
11 slope sectional 2) < 55° 
(plane slope 
figure) 
Slopes with 
10 certain 2) 
indication 
3 eem 1-99 
  
775377 
slope 
Concave Convex 
5 slope sectional (ff 
(plane slope 
figure) Slo : 
pes with 
7 certain Z 
indication v 
6 Concave 
sectional (« 
slope 
  
  
  
  
  
  
  
  
Figure 3 Topographic Division 
3. HOW TO DECIDE THE OPTIMAL ROUTE 
This system uses principally the minimum weight 
of tower as an index of the optimal route. The 
weight of tower has the following restrictions from 
the designing standpoints. 
1. The tower installed at point "i" as shown in 
Figure 5 has relative horizontal (0,) and verti- 
cal angles (h/s) to the upstream and downstream 
towers. These two fac- 
tors determine the tow- 
er type. 
2. There is a minimum 
distance determined 
between the electric 
wire and the ground. 
Securing this distance 
and the minimum sum of 
the weights of the 
towers including the 
upstream and  down- 
Stream ones permit us 
to decide the tower 
height. 
3. The tower type and 
height thus decided 
allow to have the 
  
  
  
tower weight desired Figure 4 
(w,) . Distribution of Se- 
lectable Locations 
of Tower 
  
  
  
  
= 3 i+] 
  
E 
Figure 5 Relationship between the Towers