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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 
  
  
  
  
Figure 5. Local plans coverage (840,000 km2) 
The LANDSAT-7 images were orthorectified using GCPs 
spaced at about 50 km spacing and DEMs of 30 m postings. 
A geometric accuracy of about 15 — 20 m was achieved. The 
landuse of about 20 categories were derived using these 
images. 
The IKONOS and QuickBird images were orthorectified 
using GCPs spaced at about 5 km spacing and DEMs of 10 m 
postings. A total of about 6000 GCPs were established. A 
geometric accuracy of about 1.0 — 1.5 m was achieved. This 
is probably one of the biggest and most successful projects 
solving the need of fundamental geodatabase of a country. 
A seamless database of 100,000 km2 was established using 
orthorectified IKONOS and QuickBird images. Thus, Saudi 
Arabia has a very reliable, georeferenced and complete HRS 
image database which will be the foundation for other spatial 
data such as telephone network, land database, planning, etc. 
The orthorectified IKONOS & QuickBird images were 
checked by the Consultant of the project independently. For 
checking purposes 9-16 uniformly distributed points were 
picked in 9 areas covered by IKONOS images. These points 
were GPS surveyed and these coordinates were compared 
against those read from orthorectified images. The RMS 
values obtained from comparison are tabulated in Table 2. 
The overall RMS value of comparison is 1.59 m. The tests in 
other areas are under progress. 
Table 2. Orthorectified IKONOS test results 
  
  
  
  
  
AREA Number of/RMS ERROR 
REGION |(km2) [Test Points |(m) 
Najran 1620 8 2.02 
Gizan 2205 19 1.59 
Aseer 3050 }15 1.79 
Baha 1600 |12 0.88 
Hail 1010 [9 1.04 
Arar 1750. 113 1.33 
Riyadh 7330412 2.29 
Jeddah 4840 |14 1.32 
Dammam [4370 116 1.60 
108 1.59 m 
  
  
  
  
First, possible DEM collection techniques were examined, 
including using Russian TK-350 stereo photographs 
(Fomtchenko et al., 2000). Since our tests have not yielded 
satisfactory results, we decided to use existing topographic 
maps. The DEMs used in the orthorectification of IKONOS 
& QuickBird images were compiled from topographic maps 
of 1/10000 — 1/50000 depending on the roughness of the 
topography. The compiled DEMs were checked by external 
control measurements For this purpose, a total of 1242 
checkpoints / GCPs which have height accuracy better than 1 
m. These heights were compared against those obtained from 
DEMs’ database. The RMS values obtained from comparison 
are tabulated for each area in Table 3. The overall RMS 
value is 6.48 m. Additional tests and comparisons are under 
way. 
Table 3. IKONOS / QuickBird DEM areas and test results 
Najran 1620 2.54 m 
Gizan 2205 7.34 m 
Aseer 3050 8.02 m 
Baha 1600 2 6.90 m 
Hail 1010 7.18 m 
Ri 7330 6.83 m 
Jeddah 4840 5.66 m 
Dammam 4370 4.64 m 
Arar 1750 5.74m 
  
3.2 Planning Geodatabase 
Ministry of Municipal and Rural Affairs is responsible for 
planning of Saudi Arabia. The Ministry had structural and 
local plans, all as hardcopy and lacking acceptable geometric 
accuracy, standard and format. One good example to this 
problem is illustrated in Fig. 6. Over 2000 structural plans, 
Which covers the entire S. Arabia (13 regions), were digitized 
and georegistered using existing topographic maps and 
LANDSAT-7 database mentioned above. 
As can be seen in Table 4, For 3 regions, namely Qaseem, 
Riyadh and Aseer (see Fig. 5), over 29,000. km2 of IKONOS 
and QuickBird images were used to i) update structural plans 
of 685 sheet (see Table 5) ii) rectify local and subdivision 
plans of 619 sheet (see Table 6). 
      
Table 4. Ikonos / QuickBird Satellite Images Used 
ie = TL RR RE