Table 3. Line Segment Data Sets 
FEATURE 
SEGMENT 
FEATURE A 
//SEG = 2 
F*/SÈG 1** 
F/SEG 2 
FEAT B 
// SEG = 4 
R/SEG = 2 
F/SEG 3 
F/SEG 4 
F/SEG 3 
FEAT C 
SEG 1 
FEAT COUNT = 1 
FEAT A 
// POINTS IN SEG 
X v Y v Z [t 
• 
Xn, Yn, Zn, 
SEG 2 
FEA COUNT = 2 
FEA? A 
FEAT B 
// POINTS IN SEG 
y "Y 7 
A u V A i» 
Xn, Yn, Zn, 
SEG 5 
FEA COUNT = 2 
FEAT B 
Direction of segment (Forward (F) on Reverse (R)). 
** Segment list is ordered to track the feature boundary. 
DCAD 
I3Z 
N / 
I DVOD 
DFAD 
DTED *** 
CHARTING **** 
Figure 4. Product Requirements 
*** Potential for storage in DCAD format but possibly will be maintained 
as separate DTED data base. 
**** If DFAD specifications expanded to include charting requirement, the 
specifications will essentially become one. 
A further key element in the DCAD creation process is the investigation and 
design of a classification coding scheme to allow the selection of a specified 
class of cartographic features to support mulit-series production requirements.