International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004 
ground sample distances or "pixel" sizes are 49 feet (15 
meters) in the panchromatic band; 98 feet (30 meters) in the 6 
visible, near and short-wave infrared bands; and 197 feet (60 
meters) in the thermal infrared band. 
The satellite orbits the Earth at an altitude of approximately 
438 miles (705 kilometers) with a sun-synchronous 98-degree 
inclination and a descending equatorial crossing time of 10 
am. LANDSAT Worldwide Reference System will be 
maintained with periodic adjustments for the life of the 
mission. A three-axis attitude control subsystem stabilizes the 
satellite and keeps the instrument pointed toward Earth to 
within 0.05 degrees. The LANDSAT World-Wide-Reference 
system catalogues the worlds landmass into 57,784 scenes, 
each 115 miles (183 kilometers) wide by 106 miles (170 
kilometers) long. The ETM+ will produce approximately 3.8 
gigabits of data for each scene, which is roughly equivalent to 
nearly 15 sets of encyclopedias at 29 volumes per set. 
An example of the combination of 3,2,1 bands were given in 
Figure 1. 
  
Figure 1. LANDSAT Imagery of Marmara Sea (Bands 3,2,1) 
Researchers familiar with earlier Landsat 4 and 5 data will 
note the addition of a 15-meter panchromatic band, two gain 
ranges, the improved 60-meter spatial resolution for the 
thermal band, and the addition of two solar calibrators that 
contribute to improved radiometric calibration accuracy (Table 
1). 
  
  
  
  
  
  
  
  
  
  
| Band Number Spectral Range Ground Resolution 
i microns n 
| 1 45 to .515 30 
| 2 525 to .605 30 
3 ‚63102690: £13 vaa £301: 1.4] 
4 75 to .90 Ne 
5 1.55 to 1.75 30 
6 10.40 to 12.5 60 
| 7 2.09 to 2.35 30 
| Pan .52 to .90 15 
  
  
  
  
Table 1. LANDSAT 7 Spectral and Spatial Resolution 
Imagery is available from EROS Data Center DAAC in Level 
OR (essentially raw data), IR (radiometrically corrected OR) 
450 
and 1G (radiometrically and systematically corrected OR) 
processing levels. During processing, the OR image data 
undergo two-dimensional resampling according to user- 
specified parameters including output map projection, rotation 
angle, pixel size, and resampling kernel. Standard data are 
provided via CD, 8mm tape or electronically via FTP 
(LANDSAT Project). 
2.2 The Production Process of Turkey’s Ortophoto Mosaic 
It was decided that Landsat imagery would be used for the 
project. After planning and looking for the archives, 60 
Landsat images (between years 2000-2004) that have overlap 
and sidelap were selected. Orthoengine Tool of PCI Geomatica 
software was used to produce orthophotos and the mosaic. 
1:50.000 scale topographic raster maps were used as a base for 
Ground Control Points. 
The production process followed the workflow as seen in 
Figure 2: 
Planning and 
selection of the 
imagery from 
archives 
Collection of Tie 
Points and 
Ground Control 
Points 
Production of 
orthophotos and 
mosaicing 
Production of 3D 
perspective and 
superimposition 
of vector data 
  
Figure 2. Production workflow 
A total number of 400 Ground Control Points (GCP) and 720 
Tie Points (TP) were collected for triangulation. After bundle 
block adjustment, the results; XRMS=16.42 m., YRMS=24.46 
m. for GCP and XRMS=12.93 m., YRMS=12.56 m. for TP 
were obtained. The results were very good if the 30 meters 
pixel size was taken into consideration. It corresponds nearly 
the accuracy of 1:100.000 scale maps, but the detection of the 
features is good for 1:250.000 scale maps. A part of block is 
shown in Figure 3. 
  
Internatio! 
e EH 
After the 
productio: 
Elevation 
mosaickec 
3D visual 
Road and 
towns, riv 
  
Figur 
Also with 
of GCM, 
some othe